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Re: setting up postscreen on a system with multiple external interfaces

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  • Erik Slagter
    ... Yes I did (of course). The README does NOT give any information on the use of multiple interfaces. It says change ... into ... but my master file doesn t
    Message 1 of 25 , Feb 21, 2013
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      On 21-02-13 13:04, DTNX Postmaster wrote:

      >> Please help me with the following. I have here a postfix system that
      >> listens on multiple (external) interfaces, e.g. one of them receives
      >> e-mail from the internet, one of them receives more or less secure mail
      >> from associated institutions.
      >>
      >> E-mail received on the "internet" interface receives full processing,
      >> including amavis which calls spamassassin (by proxy filter) and it
      >> should offer "may" level TLS (no discussion about that please ;-)).
      >>
      >> The e-mail received on the "secure" interface receives limited
      >> processing, e.g. no amavis and it doesn't need to offer TLS.
      >>
      >> Besides that there are also a few "internal" interfaces postfix listens
      >> on as well, with minimal processing, but with dkim signing.
      >>
      >> So there are actually multiple flows through the system, depending on
      >> the interface the mail was received on.
      >>
      >> I want to start using postscreen. Of course I am not going to "test" in
      >> a production environment, so I made a comparable postfix installation
      >> and with that installation I ran into a problem:
      >>
      >> The options (-o) that I specify on the various per-interface smtpd
      >> instances are NOT honoured anymore. I can check that quite easily
      >> because the hello string varies per interface and also TLS is no longer
      >> offered (disabled in the main.cf and enable on a per-interface basis in
      >> the master.cf file). When I revert to non-postscreen operation, it works
      >> like expected.
      >>
      >> Is this intentional? A know bug? Or something I should do another way?
      >> Anyone that has this configuration running, with postscreen?
      >>
      >> I must say the "howto" isn't very clear on this matter, it assumes you
      >> only have only one external interface.
      >>
      >> Thanks in advance.
      >
      > http://www.postfix.org/POSTSCREEN_README.html
      > Have you followed those instructions?

      Yes I did (of course).

      The README does NOT give any information on the use of multiple
      interfaces. It says "change ... into ..." but my master file doesn't
      have these lines. It would be much better if it would explain HOW it
      works so you can do the adjustments yourself.

      > AFAIK, you can bind 'postscreen' to a specific interface by specifying
      > a hostname or an IP address in front of the port name or number in
      > 'master.cf';
      >
      > 192.0.2.1:smtp inet .... postscreen
      >
      > And then have a regular Postfix instance on a seperate address;
      >
      > 192.0.2.2:smtp inet .... smtpd

      I tried another variant:

      192.168.0.1:smtp inet ... postscreen
      -o options...

      192.168.0.1:pass inet ... smtpd
      -o options...

      This resembles the approach in the README most closely.

      Postfix does start, but it doesn't honour the options, on both
      instances. It's very simple to check, because I have postcheck report
      another welcome string on every interface. Now it shows the "default"
      welcome string, without postscreen, it gives the proper welcome string.

      > If you cannot simplify your setup, you may need this;
      > http://www.postfix.org/MULTI_INSTANCE_README.html

      Read that too. It is not completely clear to me, but I suspect this
      gives me multiples queues too, which is not what I want, I want to route
      e-mail between all interfaces.

      > Other than that, post proof that options are not honored anymore. The
      > most likely cause is that you are trying to apply something to
      > 'postscreen' that is only supported for 'smtpd'?

      See above, SMTP welcome string. Which I added as an option to both the
      smtpd and the postscreen line... None of them were honoured.
    • Birta Levente
      ... It s mine: postscreen_greet_banner = $smtpd_banner/Postscreen enabled
      Message 2 of 25 , Feb 21, 2013
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        On 21/02/2013 15:32, Erik Slagter wrote:
        > On 21-02-13 13:04, DTNX Postmaster wrote:
        >
        >>> Please help me with the following. I have here a postfix system that
        >>> listens on multiple (external) interfaces, e.g. one of them receives
        >>> e-mail from the internet, one of them receives more or less secure mail
        >>> from associated institutions.
        >>>
        >>> E-mail received on the "internet" interface receives full processing,
        >>> including amavis which calls spamassassin (by proxy filter) and it
        >>> should offer "may" level TLS (no discussion about that please ;-)).
        >>>
        >>> The e-mail received on the "secure" interface receives limited
        >>> processing, e.g. no amavis and it doesn't need to offer TLS.
        >>>
        >>> Besides that there are also a few "internal" interfaces postfix listens
        >>> on as well, with minimal processing, but with dkim signing.
        >>>
        >>> So there are actually multiple flows through the system, depending on
        >>> the interface the mail was received on.
        >>>
        >>> I want to start using postscreen. Of course I am not going to "test" in
        >>> a production environment, so I made a comparable postfix installation
        >>> and with that installation I ran into a problem:
        >>>
        >>> The options (-o) that I specify on the various per-interface smtpd
        >>> instances are NOT honoured anymore. I can check that quite easily
        >>> because the hello string varies per interface and also TLS is no longer
        >>> offered (disabled in the main.cf and enable on a per-interface basis in
        >>> the master.cf file). When I revert to non-postscreen operation, it works
        >>> like expected.
        >>>
        >>> Is this intentional? A know bug? Or something I should do another way?
        >>> Anyone that has this configuration running, with postscreen?
        >>>
        >>> I must say the "howto" isn't very clear on this matter, it assumes you
        >>> only have only one external interface.
        >>>
        >>> Thanks in advance.
        >>
        >> http://www.postfix.org/POSTSCREEN_README.html
        >> Have you followed those instructions?
        >
        > Yes I did (of course).
        >
        > The README does NOT give any information on the use of multiple
        > interfaces. It says "change ... into ..." but my master file doesn't
        > have these lines. It would be much better if it would explain HOW it
        > works so you can do the adjustments yourself.
        >
        >> AFAIK, you can bind 'postscreen' to a specific interface by specifying
        >> a hostname or an IP address in front of the port name or number in
        >> 'master.cf';
        >>
        >> 192.0.2.1:smtp inet .... postscreen
        >>
        >> And then have a regular Postfix instance on a seperate address;
        >>
        >> 192.0.2.2:smtp inet .... smtpd
        >
        > I tried another variant:
        >
        > 192.168.0.1:smtp inet ... postscreen
        > -o options...
        >
        > 192.168.0.1:pass inet ... smtpd
        > -o options...
        >
        > This resembles the approach in the README most closely.
        >
        > Postfix does start, but it doesn't honour the options, on both
        > instances. It's very simple to check, because I have postcheck report
        > another welcome string on every interface. Now it shows the "default"
        > welcome string, without postscreen, it gives the proper welcome string.
        >

        It's mine:

        postscreen_greet_banner = $smtpd_banner/Postscreen enabled




        >> If you cannot simplify your setup, you may need this;
        >> http://www.postfix.org/MULTI_INSTANCE_README.html
        >
        > Read that too. It is not completely clear to me, but I suspect this
        > gives me multiples queues too, which is not what I want, I want to route
        > e-mail between all interfaces.
        >
        >> Other than that, post proof that options are not honored anymore. The
        >> most likely cause is that you are trying to apply something to
        >> 'postscreen' that is only supported for 'smtpd'?
        >
        > See above, SMTP welcome string. Which I added as an option to both the
        > smtpd and the postscreen line... None of them were honoured.
        >
      • Birta Levente
        ... As I understand, you verify the new postscreen enabled configuration with welcome string, which as I understand is the smtp banner. Postscreen enabled smtp
        Message 3 of 25 , Feb 21, 2013
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          On 21/02/2013 15:56, Erik Slagter wrote:
          > On 21-02-13 14:41, Birta Levente wrote:
          >>> Postfix does start, but it doesn't honour the options, on both
          >>> instances. It's very simple to check, because I have postcheck report
          >>> another welcome string on every interface. Now it shows the "default"
          >>> welcome string, without postscreen, it gives the proper welcome string.
          >>
          >> It's mine:
          >>
          >> postscreen_greet_banner = $smtpd_banner/Postscreen enabled
          >
          > I don't understand?
          >

          As I understand, you verify the new postscreen enabled configuration
          with welcome string, which as I understand is the smtp banner.

          Postscreen enabled smtp banner is set by postscreen_greet_banner.

          Levi
        • DTNX Postmaster
          ... [snip] ... Postscreen has its own set of options. Read the documentation; http://www.postfix.org/postscreen.8.html Also, avoid trying to optimize for
          Message 4 of 25 , Feb 21, 2013
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            On Feb 21, 2013, at 14:32, Erik Slagter <erik@...> wrote:

            > On 21-02-13 13:04, DTNX Postmaster wrote:
            >
            >> http://www.postfix.org/POSTSCREEN_README.html
            >> Have you followed those instructions?
            >
            > Yes I did (of course).
            >
            > The README does NOT give any information on the use of multiple
            > interfaces. It says "change ... into ..." but my master file doesn't
            > have these lines. It would be much better if it would explain HOW it
            > works so you can do the adjustments yourself.

            [snip]

            >> Other than that, post proof that options are not honored anymore. The
            >> most likely cause is that you are trying to apply something to
            >> 'postscreen' that is only supported for 'smtpd'?
            >
            > See above, SMTP welcome string. Which I added as an option to both the
            > smtpd and the postscreen line... None of them were honoured.

            Postscreen has its own set of options. Read the documentation;

            http://www.postfix.org/postscreen.8.html

            Also, avoid trying to 'optimize' for cosmetic reasons. Things like the
            welcome string are generally only seen by machines, have no impact on
            the operation of the mail server in general, and so on. But if you
            cannot resist doing so, this may be what you are looking for;

            http://www.postfix.org/postconf.5.html#postscreen_greet_banner

            Cya,
            Jona
          • Erik Slagter
            ... man postscreen. The postscreen (and fwiw tslproxy) has it s own set of options which are... by default... copied from the standard smtpd_* options! Also
            Message 5 of 25 , Feb 21, 2013
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              On 21-02-13 15:29, DTNX Postmaster wrote:
              >> See above, SMTP welcome string. Which I added as an option to both the
              >> smtpd and the postscreen line... None of them were honoured.
              >
              > Postscreen has its own set of options. Read the documentation;
              > http://www.postfix.org/postscreen.8.html

              man postscreen.

              The postscreen (and fwiw tslproxy) has it's own set of options which
              are... by default... copied from the standard smtpd_* options!

              Also tried it with setting these options explicitly (with no success),
              but didn't want to flood information.

              > Also, avoid trying to 'optimize' for cosmetic reasons. Things like the
              > welcome string are generally only seen by machines, have no impact on
              > the operation of the mail server in general, and so on. But if you
              > cannot resist doing so, this may be what you are looking for;
              >
              > http://www.postfix.org/postconf.5.html#postscreen_greet_banner

              The welcome string is very important for me, because, as may be obvious
              now, that's a very quick way to check if per-interface settings are
              honoured. This is completely NOT about the welcome string on itself,
              it's about per-interface options not being honoured, so I end up without
              TLS support on the outside interface, whilst if I disable postscreen, it
              simply works!

              The only thing I need is an example of a master.cf file where postfix
              listens on various interfaces with different options, and then the same
              with postscreen enabled and still working (i.e. the per-interface smtpd
              options are honoured).

              Or a good explanation of the workflow of postscreen, a.o. what the two
              "example" lines in the README actually do, so I can adapt that to my
              situation.

              Thx.
            • Wietse Venema
              ... If you don t show the exact options and the exact logging then no-one can say what mistake YOU are making. Wietse
              Message 6 of 25 , Feb 21, 2013
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                Erik Slagter:
                > I tried another variant:
                >
                > 192.168.0.1:smtp inet ... postscreen
                > -o options...
                >
                > 192.168.0.1:pass inet ... smtpd
                > -o options...

                If you don't show the exact options and the exact logging
                then no-one can say what mistake YOU are making.

                Wietse
              • Erik Slagter
                ... Okay, I didn t post the complete master.cf because I thought it wouldn t be necessary, so here it comes. This is the plain version that works, without
                Message 7 of 25 , Feb 21, 2013
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                  On 21-02-13 15:50, Wietse Venema wrote:
                  > Erik Slagter:
                  >> I tried another variant:
                  >>
                  >> 192.168.0.1:smtp inet ... postscreen
                  >> -o options...
                  >>
                  >> 192.168.0.1:pass inet ... smtpd
                  >> -o options...
                  >
                  > If you don't show the exact options and the exact logging
                  > then no-one can say what mistake YOU are making.

                  Okay, I didn't post the complete master.cf because I thought it wouldn't
                  be necessary, so here it comes. This is the "plain" version that works,
                  without postscreen enabled. If somebody can explain to me how to
                  transform this into something working with postscreen enabled AND TLS
                  working on the outside interface (ppp0, ipv4 and ipv6), I'd be very
                  grateful, but really I've tried various approaches without luck.
                  Postscreen on itself is working fine, btw.

                  # ==========================================================================
                  # service type private unpriv chroot wakeup maxproc command + args
                  # (yes) (yes) (yes) (never) (100)
                  # ==========================================================================

                  #smtp inet n - n - 1 smtpd
                  #smtp inet n - n - 1 postscreen
                  #smtpd pass - - n - - smtpd
                  #dnsblog unix - - n - 0 dnsblog
                  #tlsproxy unix - - n - 0 tlsproxy

                  #
                  # outside -> inside
                  # postfix(25) -> amavis(10025)
                  #

                  mx1.ipv4.slagter.name:smtp inet n - n - 2 smtpd
                  -o myhostname=eriks.xs4all.nl
                  -o smtpd_banner=mx1.slagter.name-ESMTP-$mail_name-mx1-ppp0-ipv4-25
                  -o smtpd_tls_security_level=may
                  -o postscreen_tls_security_level=may
                  -o tlsproxy_tls_security_level=may
                  -o smtpd_proxy_filter=nemesis.ipv4:10025
                  -o soft_bounce=no
                  -o postscreen_cache_map=btree:$data_directory/postscreen_cache-ipv4

                  mx1.ipv6.slagter.name:smtp inet n - n - 2 smtpd
                  -o myhostname=mx1.ipv6.slagter.name
                  -o smtpd_banner=mx1.slagter.name-ESMTP-$mail_name-mx1-ppp0-ipv6-25
                  -o smtpd_tls_security_level=may
                  -o postscreen_tls_security_level=may
                  -o tlsproxy_tls_security_level=may
                  -o smtpd_proxy_filter=nemesis.ipv4:10025
                  -o soft_bounce=no
                  -o postscreen_cache_map=btree:$data_directory/postscreen_cache-ipv6

                  #
                  # amavis(10025) -> postfix(10026)
                  #

                  nemesis.ipv4:10026 inet n - n - 2 smtpd
                  -o smtpd_recipient_restrictions=permit_mynetworks,reject
                  -o
                  receive_override_options=no_unknown_recipient_checks,no_header_body_checks
                  -o body_checks=
                  -o header_checks=
                  -o myhostname=nemesis.slagter.name
                  -o smtp_helo_name=nemesis.slagter.name
                  -o smtpd_banner=nemesis.slagter.name-ESMTP-$mail_name-lo-ipv4-10026
                  -o smtpd_client_restrictions=
                  -o smtpd_authorized_xforward_hosts=10.1.1.1

                  #
                  # postfix(25) -> dkimproxy(11025)
                  #

                  nemesis.ipv4:smtp inet n - n - 2 smtpd
                  -o smtpd_recipient_restrictions=permit_mynetworks,reject
                  -o body_checks=
                  -o header_checks=
                  -o myhostname=nemesis.slagter.name
                  -o smtp_helo_name=nemesis.slagter.name
                  -o smtpd_banner=nemesis.slagter.name-ESMTP-$mail_name-eth0-ipv4-25
                  -o mynetworks=127.0.0.0/8
                  -o smtpd_proxy_filter=nemesis.ipv4:11025

                  nemesis.ipv6:smtp inet n - n - 2 smtpd
                  -o smtpd_recipient_restrictions=permit_mynetworks,reject
                  -o body_checks=
                  -o header_checks=
                  -o myhostname=nemesis.slagter.name
                  -o smtp_helo_name=nemesis.slagter.name
                  -o smtpd_banner=nemesis.slagter.name-ESMTP-$mail_name-eth0-ipv6-25
                  -o smtpd_proxy_filter=nemesis.ipv4:11025

                  #
                  # dkimproxy(11025) -> postfix(11026)
                  #

                  nemesis.ipv4:11026 inet n - n - 2 smtpd
                  -o smtpd_recipient_restrictions=permit_mynetworks,reject
                  -o
                  receive_override_options=no_unknown_recipient_checks,no_header_body_checks
                  -o body_checks=
                  -o header_checks=
                  -o myhostname=nemesis.slagter.name
                  -o smtp_helo_name=nemesis.slagter.name
                  -o smtpd_banner=nemesis.slagter.name-ESMTP-$mail_name-lo-ipv4-11026
                  -o smtpd_client_restrictions=
                  -o smtpd_authorized_xforward_hosts=10.1.1.1

                  #
                  # locally generated
                  #

                  #localhost.ipv4:smtp inet n - n - - postscreen
                  localhost.ipv4:smtp inet n - n - - smtpd
                  -o smtpd_recipient_restrictions=permit_mynetworks,reject
                  -o body_checks=
                  -o header_checks=
                  -o myhostname=nemesis.slagter.name
                  -o smtp_helo_name=nemesis.slagter.name
                  -o smtpd_banner=nemesis.slagter.name-ESMTP-$mail_name-lo-ipv4-25
                  -o mynetworks=127.0.0.0/8

                  #nemesis.ipv4:smtp inet n - n - - postscreen
                  nemesis.ipv4:smtp inet n - n - - smtpd
                  -o smtpd_recipient_restrictions=permit_mynetworks,reject
                  -o body_checks=
                  -o header_checks=
                  -o myhostname=nemesis.slagter.name
                  -o smtp_helo_name=nemesis.slagter.name
                  -o smtpd_banner=nemesis.slagter.name-ESMTP-$mail_name-vlan2-alt-ipv4-25
                  -o mynetworks=10.0.2.0/24

                  ::1:smtp inet n - n - - smtpd
                  -o smtpd_recipient_restrictions=permit_mynetworks,reject
                  -o body_checks=
                  -o header_checks=
                  -o myhostname=nemesis.slagter.name
                  -o smtp_helo_name=nemesis.slagter.name
                  -o smtpd_banner=nemesis.slagter.name-ESMTP-$mail_name-lo-ipv6-25

                  pickup fifo n - n 60 1 pickup
                  cleanup unix n - n - 0 cleanup
                  qmgr fifo n - n 300 1 qmgr
                  tlsmgr unix - - n 1000? 1 tlsmgr
                  rewrite unix - - n - - trivial-rewrite
                  bounce unix - - n - 0 bounce
                  defer unix - - n - 0 bounce
                  trace unix - - n - 0 bounce
                  verify unix - - n - 1 verify
                  flush unix n - n 1000? 0 flush
                  proxymap unix - - n - - proxymap
                  smtp unix - - n - - smtp
                  relay unix - - n - - smtp -o
                  smtp_helo_timeout=5 -o smtp_connect_timeout=5
                  showq unix n - n - - showq
                  error unix - - n - - error
                  local unix - n n - - local
                  virtual unix - n n - - virtual
                  lmtp unix - - n - - lmtp
                  anvil unix - - n - 1 anvil

                  smtp-inside unix - - n - - smtp
                  -o myhostname=nemesis.slagter.name
                  -o smtp_helo_name=nemesis.slagter.name
                  -o smtp_bind_address6=2001:980:5fef:1::1

                  smtp-default unix - - n - - smtp
                  -o myhostname=eriks.xs4all.nl
                  -o smtp_helo_name=eriks.xs4all.nl
                  -o smtp_bind_address6=2001:980:5fef::1
                  -o smtp_tls_security_level=may
                • Wietse Venema
                  ... TO REPORT A PROBLEM see http://www.postfix.org/DEBUG_README.html#mail TO (UN)SUBSCRIBE see http://www.postfix.org/lists.html Thank you for using Postfix.
                  Message 8 of 25 , Feb 21, 2013
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                    Erik Slagter:
                    > On 21-02-13 15:50, Wietse Venema wrote:
                    > > Erik Slagter:
                    > >> I tried another variant:
                    > >>
                    > >> 192.168.0.1:smtp inet ... postscreen
                    > >> -o options...
                    > >>
                    > >> 192.168.0.1:pass inet ... smtpd
                    > >> -o options...
                    > >
                    > > If you don't show the exact options and the exact logging
                    > > then no-one can say what mistake YOU are making.
                    >
                    > Okay, I didn't post the complete master.cf because I thought it wouldn't
                    > be necessary, so here it comes. This is the "plain" version that works,
                    > without postscreen enabled. If somebody can explain to me how to

                    TO REPORT A PROBLEM see http://www.postfix.org/DEBUG_README.html#mail

                    TO (UN)SUBSCRIBE see http://www.postfix.org/lists.html

                    Thank you for using Postfix.
                  • Erik Slagter
                    ... And I always thought I could be blunt at moments ;-) PROBLEM (apparently this is a problem ) * Summary Setting up postscreen on a system with multiple
                    Message 9 of 25 , Feb 21, 2013
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                      On 21-02-13 16:16, Wietse Venema wrote:
                      > Erik Slagter:
                      > TO REPORT A PROBLEM see http://www.postfix.org/DEBUG_README.html#mail
                      > TO (UN)SUBSCRIBE see http://www.postfix.org/lists.html
                      > Thank you for using Postfix.

                      And I always thought I could be blunt at moments ;-)

                      PROBLEM (apparently this is a "problem")

                      * Summary

                      Setting up postscreen on a system with multiple external interfaces
                      causes per-interface smtpd options not to be honoured

                      * Complete error messages

                      None.

                      * Postfix logging

                      None relevant (really! the logging is exactly the same for postscreen
                      and non-postscreen operation, up to the problem the problem occurs).

                      * Postconf -n

                      alias_database = hash:/etc/postfix/aliases
                      alias_maps = hash:/etc/postfix/aliases
                      allow_mail_to_commands = alias,forward
                      allow_mail_to_files = alias,forward
                      append_at_myorigin = yes
                      append_dot_mydomain = yes
                      command_time_limit = 300
                      config_directory = /etc/postfix
                      data_directory = /var/lib/postfix
                      default_destination_concurrency_limit = 2
                      default_privs = amavis
                      default_transport = smtp-default
                      delay_warning_time = 4
                      fast_flush_domains = $mydomain
                      inet_protocols = ipv6 ipv4
                      local_destination_concurrency_limit = 2
                      local_transport = local
                      mail_owner = postfix
                      mailbox_size_limit = 0
                      masquerade_domains = $mydomain
                      masquerade_exceptions = root
                      maximal_backoff_time = 1h
                      maximal_queue_lifetime = 21d
                      message_size_limit = 100000000
                      minimal_backoff_time = 2m
                      mydestination = nemesis.slagter.name, eriks.xs4all.nl, $myhostname,
                      localhost.$mydomain, localhost
                      mydomain = slagter.name
                      myhostname = nemesis.slagter.name
                      mynetworks = 10.0.0.0/8, 127.0.0.0/8, [2001:980:5fef::]/48 [::1]/128
                      [fe80::]/10
                      myorigin = $mydomain
                      notify_classes = bounce,2bounce,data,delay,resource,software
                      postscreen_access_list = permit_mynetworks,
                      cidr:/etc/postfix/postscreen_access.cidr
                      postscreen_bare_newline_action = enforce
                      postscreen_bare_newline_enable = yes
                      postscreen_blacklist_action = enforce
                      postscreen_cache_retention_time = 30d
                      postscreen_greet_action = enforce
                      postscreen_greet_banner = $smtpd_banner postscreen
                      postscreen_greet_ttl = 1h
                      postscreen_greet_wait = 2s
                      postscreen_non_smtp_command_action = enforce
                      postscreen_non_smtp_command_enable = yes
                      postscreen_pipelining_enable = yes
                      queue_directory = /var/spool/postfix
                      queue_minfree = 0
                      queue_run_delay = 5m
                      recipient_delimiter = +
                      relay_domains = slagter.name, erikslag@..., eriks.xs4all.nl
                      setgid_group = postdrop
                      smtp_helo_name = eriks.xs4all.nl
                      smtp_send_xforward_command = yes
                      smtp_tls_block_early_mail_reply = yes
                      smtp_tls_cert_file = /etc/postfix/mx1_slagter_name_all_crt.pem
                      smtp_tls_key_file = /etc/postfix/mx1_slagter_name_key.pem
                      smtp_tls_loglevel = 1
                      smtp_tls_security_level = none
                      smtpd_authorized_xforward_hosts = 127.0.0.0/8,10.1.0.0/16,10.0.0.0/16
                      smtpd_banner = $myhostname ESMTP $mail_name
                      smtpd_client_restrictions = permit
                      smtpd_delay_reject = no
                      smtpd_etrn_restrictions = permit
                      smtpd_helo_required = yes
                      smtpd_helo_restrictions = permit
                      smtpd_recipient_restrictions = reject_non_fqdn_recipient
                      reject_unauth_destination check_recipient_access
                      hash:/etc/postfix/local_users permit
                      smtpd_sender_restrictions = permit
                      smtpd_tls_ask_ccert = yes
                      smtpd_tls_cert_file = /etc/postfix/mx1_slagter_name_all_crt.pem
                      smtpd_tls_dh1024_param_file = /etc/postfix/dh_1024.pem
                      smtpd_tls_dh512_param_file = /etc/postfix/dh_512.pem
                      smtpd_tls_key_file = /etc/postfix/mx1_slagter_name_key.pem
                      smtpd_tls_loglevel = 1
                      smtpd_tls_received_header = yes
                      smtpd_tls_req_ccert = no
                      smtpd_tls_security_level = none
                      strict_rfc821_envelopes = no
                      tls_random_source = dev:/dev/urandom
                      transport_maps = hash:/etc/postfix/transport
                      virtual_alias_maps = hash:/etc/postfix/virtual

                      * Postfinger

                      ostfinger - postfix configuration on do feb 21 16:32:28 CET 2013
                      version: 1.30

                      Warning: postfinger output may show private configuration information,
                      such as ip addresses and/or domain names which you do not want to show
                      to the public. If this is the case it is your responsibility to modify
                      the output to hide this private information. [Remove this warning with
                      the --nowarn option.]

                      --System Parameters--
                      mail_version = 2.9.4
                      hostname = nemesis
                      uname = Linux nemesis 3.5.3 #1 SMP Thu Aug 30 18:52:19 CEST 2012 x86_64
                      x86_64 x86_64 GNU/Linux

                      --Packaging information--
                      looks like this postfix comes from RPM package: postfix-2.9.4-2.fc17.x86_64

                      --main.cf non-default parameters--
                      alias_database = hash:/etc/postfix/aliases
                      alias_maps = hash:/etc/postfix/aliases
                      allow_mail_to_commands = alias,forward
                      allow_mail_to_files = alias,forward
                      command_time_limit = 300
                      default_destination_concurrency_limit = 2
                      default_privs = amavis
                      default_transport = smtp-default
                      delay_warning_time = 4
                      fast_flush_domains = $mydomain
                      inet_protocols = ipv6 ipv4
                      local_transport = local
                      mailbox_size_limit = 0
                      masquerade_domains = $mydomain
                      masquerade_exceptions = root
                      maximal_backoff_time = 1h
                      maximal_queue_lifetime = 21d
                      message_size_limit = 100000000
                      minimal_backoff_time = 2m
                      mydestination = nemesis.slagter.name, eriks.xs4all.nl, $myhostname,
                      localhost.$mydomain, localhost
                      mydomain = slagter.name
                      myhostname = nemesis.slagter.name
                      mynetworks = 10.0.0.0/8, 127.0.0.0/8, [2001:980:5fef::]/48 [::1]/128
                      [fe80::]/10
                      myorigin = $mydomain
                      notify_classes = bounce,2bounce,data,delay,resource,software
                      postscreen_access_list = permit_mynetworks,
                      cidr:/etc/postfix/postscreen_access.cidr
                      postscreen_bare_newline_action = enforce
                      postscreen_bare_newline_enable = yes
                      postscreen_blacklist_action = enforce
                      postscreen_cache_retention_time = 30d
                      postscreen_greet_action = enforce
                      postscreen_greet_banner = $smtpd_banner postscreen
                      postscreen_greet_ttl = 1h
                      postscreen_greet_wait = 2s
                      postscreen_non_smtp_command_action = enforce
                      postscreen_non_smtp_command_enable = yes
                      postscreen_pipelining_enable = yes
                      queue_run_delay = 5m
                      recipient_delimiter = +
                      relay_domains = slagter.name, erikslag@..., eriks.xs4all.nl
                      smtpd_authorized_xforward_hosts = 127.0.0.0/8,10.1.0.0/16,10.0.0.0/16
                      smtpd_client_restrictions = permit
                      smtpd_delay_reject = no
                      smtpd_etrn_restrictions = permit
                      smtpd_helo_required = yes
                      smtpd_helo_restrictions = permit
                      smtpd_recipient_restrictions = reject_non_fqdn_recipient
                      reject_unauth_destination check_recipient_access
                      hash:/etc/postfix/local_users permit
                      smtpd_sender_restrictions = permit
                      smtpd_tls_ask_ccert = yes
                      smtpd_tls_cert_file = /etc/postfix/mx1_slagter_name_all_crt.pem
                      smtpd_tls_dh1024_param_file = /etc/postfix/dh_1024.pem
                      smtpd_tls_dh512_param_file = /etc/postfix/dh_512.pem
                      smtpd_tls_key_file = /etc/postfix/mx1_slagter_name_key.pem
                      smtpd_tls_loglevel = 1
                      smtpd_tls_received_header = yes
                      smtpd_tls_security_level = none
                      smtp_helo_name = eriks.xs4all.nl
                      smtp_send_xforward_command = yes
                      smtp_tls_block_early_mail_reply = yes
                      smtp_tls_cert_file = /etc/postfix/mx1_slagter_name_all_crt.pem
                      smtp_tls_key_file = /etc/postfix/mx1_slagter_name_key.pem
                      smtp_tls_loglevel = 1
                      smtp_tls_security_level = none
                      transport_maps = hash:/etc/postfix/transport
                      virtual_alias_maps = hash:/etc/postfix/virtual

                      --master.cf--
                      mx1.ipv4.slagter.name:smtp inet n - n - 2 smtpd
                      -o myhostname=eriks.xs4all.nl
                      -o smtpd_banner=mx1.slagter.name-ESMTP-$mail_name-mx1-ppp0-ipv4-25
                      -o smtpd_tls_security_level=may
                      -o postscreen_tls_security_level=may
                      -o tlsproxy_tls_security_level=may
                      -o smtpd_proxy_filter=nemesis.ipv4:10025
                      -o soft_bounce=no
                      -o postscreen_cache_map=btree:$data_directory/postscreen_cache-ipv4
                      mx1.ipv6.slagter.name:smtp inet n - n - 2 smtpd
                      -o myhostname=mx1.ipv6.slagter.name
                      -o smtpd_banner=mx1.slagter.name-ESMTP-$mail_name-mx1-ppp0-ipv6-25
                      -o smtpd_tls_security_level=may
                      -o postscreen_tls_security_level=may
                      -o tlsproxy_tls_security_level=may
                      -o smtpd_proxy_filter=nemesis.ipv4:10025
                      -o soft_bounce=no
                      -o postscreen_cache_map=btree:$data_directory/postscreen_cache-ipv6
                      nemesis.ipv4:10026 inet n - n - 2 smtpd
                      -o smtpd_recipient_restrictions=permit_mynetworks,reject
                      -o
                      receive_override_options=no_unknown_recipient_checks,no_header_body_checks
                      -o body_checks=
                      -o header_checks=
                      -o myhostname=nemesis.slagter.name
                      -o smtp_helo_name=nemesis.slagter.name
                      -o smtpd_banner=nemesis.slagter.name-ESMTP-$mail_name-lo-ipv4-10026
                      -o smtpd_client_restrictions=
                      -o smtpd_authorized_xforward_hosts=10.1.1.1
                      nemesis.ipv4:smtp inet n - n - 2 smtpd
                      -o smtpd_recipient_restrictions=permit_mynetworks,reject
                      -o body_checks=
                      -o header_checks=
                      -o myhostname=nemesis.slagter.name
                      -o smtp_helo_name=nemesis.slagter.name
                      -o smtpd_banner=nemesis.slagter.name-ESMTP-$mail_name-eth0-ipv4-25
                      -o mynetworks=127.0.0.0/8
                      -o smtpd_proxy_filter=nemesis.ipv4:11025
                      nemesis.ipv6:smtp inet n - n - 2 smtpd
                      -o smtpd_recipient_restrictions=permit_mynetworks,reject
                      -o body_checks=
                      -o header_checks=
                      -o myhostname=nemesis.slagter.name
                      -o smtp_helo_name=nemesis.slagter.name
                      -o smtpd_banner=nemesis.slagter.name-ESMTP-$mail_name-eth0-ipv6-25
                      -o smtpd_proxy_filter=nemesis.ipv4:11025
                      nemesis.ipv4:11026 inet n - n - 2 smtpd
                      -o smtpd_recipient_restrictions=permit_mynetworks,reject
                      -o
                      receive_override_options=no_unknown_recipient_checks,no_header_body_checks
                      -o body_checks=
                      -o header_checks=
                      -o myhostname=nemesis.slagter.name
                      -o smtp_helo_name=nemesis.slagter.name
                      -o smtpd_banner=nemesis.slagter.name-ESMTP-$mail_name-lo-ipv4-11026
                      -o smtpd_client_restrictions=
                      -o smtpd_authorized_xforward_hosts=10.1.1.1
                      localhost.ipv4:smtp inet n - n - - smtpd
                      -o smtpd_recipient_restrictions=permit_mynetworks,reject
                      -o body_checks=
                      -o header_checks=
                      -o myhostname=nemesis.slagter.name
                      -o smtp_helo_name=nemesis.slagter.name
                      -o smtpd_banner=nemesis.slagter.name-ESMTP-$mail_name-lo-ipv4-25
                      -o mynetworks=127.0.0.0/8
                      nemesis.ipv4:smtp inet n - n - - smtpd
                      -o smtpd_recipient_restrictions=permit_mynetworks,reject
                      -o body_checks=
                      -o header_checks=
                      -o myhostname=nemesis.slagter.name
                      -o smtp_helo_name=nemesis.slagter.name
                      -o smtpd_banner=nemesis.slagter.name-ESMTP-$mail_name-vlan2-alt-ipv4-25
                      -o mynetworks=10.0.2.0/24
                      ::1:smtp inet n - n - - smtpd
                      -o smtpd_recipient_restrictions=permit_mynetworks,reject
                      -o body_checks=
                      -o header_checks=
                      -o myhostname=nemesis.slagter.name
                      -o smtp_helo_name=nemesis.slagter.name
                      -o smtpd_banner=nemesis.slagter.name-ESMTP-$mail_name-lo-ipv6-25
                      pickup fifo n - n 60 1 pickup
                      cleanup unix n - n - 0 cleanup
                      qmgr fifo n - n 300 1 qmgr
                      tlsmgr unix - - n 1000? 1 tlsmgr
                      rewrite unix - - n - - trivial-rewrite
                      bounce unix - - n - 0 bounce
                      defer unix - - n - 0 bounce
                      trace unix - - n - 0 bounce
                      verify unix - - n - 1 verify
                      flush unix n - n 1000? 0 flush
                      proxymap unix - - n - - proxymap
                      smtp unix - - n - - smtp
                      relay unix - - n - - smtp -o
                      smtp_helo_timeout=5 -o smtp_connect_timeout=5
                      showq unix n - n - - showq
                      error unix - - n - - error
                      local unix - n n - - local
                      virtual unix - n n - - virtual
                      lmtp unix - - n - - lmtp
                      anvil unix - - n - 1 anvil
                      smtp-inside unix - - n - - smtp
                      -o myhostname=nemesis.slagter.name
                      -o smtp_helo_name=nemesis.slagter.name
                      -o smtp_bind_address6=2001:980:5fef:1::1
                      smtp-default unix - - n - - smtp
                      -o myhostname=eriks.xs4all.nl
                      -o smtp_helo_name=eriks.xs4all.nl
                      -o smtp_bind_address6=2001:980:5fef::1
                      -o smtp_tls_security_level=may

                      -- end of postfinger output --

                      * All other paragraphs are not relevant.

                      Thank you for your attention.
                    • Reindl Harald
                      ... and how should this be supposed to use postscreen with smtpd instead of postscreen as command?
                      Message 10 of 25 , Feb 21, 2013
                      • 0 Attachment
                        Am 21.02.2013 16:35, schrieb Erik Slagter:

                        > mx1.ipv4.slagter.name:smtp inet n - n - 2 smtpd
                        > -o myhostname=eriks.xs4all.nl
                        > -o smtpd_banner=mx1.slagter.name-ESMTP-$mail_name-mx1-ppp0-ipv4-25
                        > -o smtpd_tls_security_level=may
                        > -o postscreen_tls_security_level=may
                        > -o tlsproxy_tls_security_level=may
                        > -o smtpd_proxy_filter=nemesis.ipv4:10025
                        > -o soft_bounce=no
                        > -o postscreen_cache_map=btree:$data_directory/postscreen_cache-ipv4

                        and how should this be supposed to use postscreen
                        with "smtpd" instead of "postscreen" as command?
                      • Erik Slagter
                        If I set up postscreen as closely as possible to the postscreen README document, I get this (diff to previous message) (I m sorry lots of it has been folded).
                        Message 11 of 25 , Feb 21, 2013
                        • 0 Attachment
                          If I set up postscreen as closely as possible to the postscreen README
                          document, I get this (diff to previous message) (I'm sorry lots of it
                          has been folded). The log says "address already in use for 10.1.1.1",
                          this is interesting because none of the changes involved 10.1.1.1.

                          --- a 2013-02-21 16:37:18.348109048 +0100
                          +++ b 2013-02-21 17:25:24.337265305 +0100
                          @@ -8,7 +8,7 @@

                          * Postfix logging

                          -None relevant (really! the logging is exactly the same for postscreen
                          and non-postscreen operation, up to the problem the problem occurs).
                          +Feb 21 16:46:03 nemesis-vlan1 postfix/master[28268]: fatal: bind
                          10.1.1.1 port 25: Address already in use

                          * Postconf -n

                          @@ -93,7 +93,7 @@

                          * Postfinger

                          -Postfinger - postfix configuration on do feb 21 16:32:28 CET 2013
                          +postfinger - postfix configuration on do feb 21 17:24:49 CET 2013
                          version: 1.30

                          Warning: postfinger output may show private configuration information,
                          @@ -178,7 +178,10 @@
                          virtual_alias_maps = hash:/etc/postfix/virtual

                          --master.cf--
                          -mx1.ipv4.slagter.name:smtp inet n - n - 2 smtpd
                          +smtp inet n - n - 1 postscreen
                          +dnsblog unix - - n - 0 dnsblog
                          +tlsproxy unix - - n - 0 tlsproxy
                          +mx1.ipv4.slagter.name:smtp pass n - n - 2 smtpd
                          -o myhostname=eriks.xs4all.nl
                          -o smtpd_banner=mx1.slagter.name-ESMTP-$mail_name-mx1-ppp0-ipv4-25
                          -o smtpd_tls_security_level=may
                          @@ -187,7 +190,7 @@
                          -o smtpd_proxy_filter=nemesis.ipv4:10025
                          -o soft_bounce=no
                          -o postscreen_cache_map=btree:$data_directory/postscreen_cache-ipv4
                          -mx1.ipv6.slagter.name:smtp inet n - n - 2 smtpd
                          +mx1.ipv6.slagter.name:smtp pass n - n - 2 smtpd
                          -o myhostname=mx1.ipv6.slagter.name
                          -o smtpd_banner=mx1.slagter.name-ESMTP-$mail_name-mx1-ppp0-ipv6-25
                          -o smtpd_tls_security_level=may
                          @@ -288,3 +291,6 @@
                          -- end of postfinger output --
                        • Erik Slagter
                          Another variation I tried ( pass and postscreen the other way around). This works, but gives the original problem, the smtpd options are not honoured
                          Message 12 of 25 , Feb 21, 2013
                          • 0 Attachment
                            Another variation I tried ("pass" and "postscreen" the other way
                            around). This works, but gives the original problem, the smtpd options
                            are not honoured (especially banner and starttls="may"), even though I
                            set both:

                            -o smtpd_tls_security_level=may
                            -o postscreen_tls_security_level=may

                            Output of postfinger, diff to first non-postscreen config:

                            --- a 2013-02-21 17:35:41.568369098 +0100
                            +++ c 2013-02-21 17:38:58.274633686 +0100
                            @@ -1,4 +1,4 @@
                            -Postfinger - postfix configuration on do feb 21 16:32:28 CET 2013
                            +postfinger - postfix configuration on do feb 21 17:38:58 CET 2013
                            version: 1.30

                            Warning: postfinger output may show private configuration information,
                            @@ -83,7 +83,10 @@
                            virtual_alias_maps = hash:/etc/postfix/virtual

                            --master.cf--
                            -mx1.ipv4.slagter.name:smtp inet n - n - 2 smtpd
                            +smtpd pass - - n - - smtpd
                            +dnsblog unix - - n - 0 dnsblog
                            +tlsproxy unix - - n - 0 tlsproxy
                            +mx1.ipv4.slagter.name:smtp inet n - n - 2 postscreen
                            -o myhostname=eriks.xs4all.nl
                            -o smtpd_banner=mx1.slagter.name-ESMTP-$mail_name-mx1-ppp0-ipv4-25
                            -o smtpd_tls_security_level=may
                            @@ -92,7 +95,7 @@
                            -o smtpd_proxy_filter=nemesis.ipv4:10025
                            -o soft_bounce=no
                            -o postscreen_cache_map=btree:$data_directory/postscreen_cache-ipv4
                            -mx1.ipv6.slagter.name:smtp inet n - n - 2 smtpd
                            +mx1.ipv6.slagter.name:smtp pass n - n - 2 postscreen
                            -o myhostname=mx1.ipv6.slagter.name
                            -o smtpd_banner=mx1.slagter.name-ESMTP-$mail_name-mx1-ppp0-ipv6-25
                            -o smtpd_tls_security_level=may

                            * Log output

                            Feb 21 17:42:40 nemesis-vlan1 postfix/master[4547]: daemon started --
                            version 2.9.4, configuration /etc/postfix
                            Feb 21 17:42:42 nemesis-vlan1 postfix/postscreen[4553]: CONNECT from
                            [10.1.1.5]:49309 to [83.163.214.71]:25
                            Feb 21 17:42:42 nemesis-vlan1 postfix/postscreen[4553]: WHITELISTED
                            [10.1.1.5]:49309
                            Feb 21 17:42:42 nemesis-vlan1 postfix/postscreen[4553]: cache
                            btree:/var/lib/postfix/postscreen_cache-ipv4 full cleanup: retained=5
                            dropped=0 entries
                            Feb 21 17:42:42 nemesis-vlan1 postfix/smtpd[4554]: connect from
                            eos.ipv4.slagter.name[10.1.1.5]
                            Feb 21 17:42:50 nemesis-vlan1 postfix/smtpd[4554]: disconnect from
                            eos.ipv4.slagter.name[10.1.1.5]
                          • Reindl Harald
                            ... postscreen != smtpd so why should it do so? http://www.postfix.org/postscreen.8.html The Postfix postscreen(8) server provides additional pro- tection
                            Message 13 of 25 , Feb 21, 2013
                            • 0 Attachment
                              Am 21.02.2013 17:46, schrieb Erik Slagter:
                              > Another variation I tried ("pass" and "postscreen" the other way around). This works, but gives the original
                              > problem, the smtpd options are not honoured (especially banner and starttls="may"), even though I set both:

                              postscreen != smtpd so why should it do so?
                              http://www.postfix.org/postscreen.8.html

                              The Postfix postscreen(8) server provides additional pro-
                              tection against mail server overload. One postscreen(8)
                              process handles multiple inbound SMTP connections, and
                              decides which clients may talk to a Postfix SMTP server
                              process.
                            • Erik Slagter
                              ... Interesting how anybody is keen on telling me I am doing it wrong, which I sort of already had figured because it doesn t work... On the other hand nobody
                              Message 14 of 25 , Feb 21, 2013
                              • 0 Attachment
                                On 21-02-13 16:45, Reindl Harald wrote:
                                > Am 21.02.2013 16:35, schrieb Erik Slagter:
                                >
                                >> mx1.ipv4.slagter.name:smtp inet n - n - 2 smtpd
                                >> [ ... ]

                                > and how should this be supposed to use postscreen
                                > with "smtpd" instead of "postscreen" as command?

                                Interesting how anybody is keen on telling me I am doing it wrong, which
                                I sort of already had figured because it doesn't work... On the other
                                hand nobody has given a hint on how to do it "right" then.

                                Likewise people pointing me to the postscreen HOWTO, which I've been
                                reading numerous times now and really does _not_ give an answer to this
                                problem.

                                >> mx1.ipv4.slagter.name:smtp inet n - n - 2 smtpd
                                >> [ ... ]

                                > and how should this be supposed to use postscreen
                                > with "smtpd" instead of "postscreen" as command?

                                Well don't ask me, I don't know, I am just trying "everything" because
                                the documentation doesn't tell me how to do it?
                              • DTNX Postmaster
                                ... You keep blaming the documentation and the software, when the problem is most likely in your understanding of it. Simplify your configuration. Don t assume
                                Message 15 of 25 , Feb 21, 2013
                                • 0 Attachment
                                  On Feb 21, 2013, at 18:28, Erik Slagter <erik@...> wrote:

                                  > On 21-02-13 16:45, Reindl Harald wrote:
                                  >> Am 21.02.2013 16:35, schrieb Erik Slagter:
                                  >>
                                  >>> mx1.ipv4.slagter.name:smtp inet n - n - 2 smtpd
                                  > >> [ ... ]
                                  >
                                  >> and how should this be supposed to use postscreen
                                  >> with "smtpd" instead of "postscreen" as command?
                                  >
                                  > Interesting how anybody is keen on telling me I am doing it wrong, which I sort of already had figured because it doesn't work... On the other hand nobody has given a hint on how to do it "right" then.
                                  >
                                  > Likewise people pointing me to the postscreen HOWTO, which I've been reading numerous times now and really does _not_ give an answer to this problem.
                                  >
                                  > >> mx1.ipv4.slagter.name:smtp inet n - n - 2 smtpd
                                  > >> [ ... ]
                                  >
                                  > > and how should this be supposed to use postscreen
                                  > > with "smtpd" instead of "postscreen" as command?
                                  >
                                  > Well don't ask me, I don't know, I am just trying "everything" because the documentation doesn't tell me how to do it?

                                  You keep blaming the documentation and the software, when the problem
                                  is most likely in your understanding of it.

                                  Simplify your configuration. Don't assume that what goes for 'smtpd'
                                  goes for 'postscreen' as well. Pick sensible defaults for 'main.cf',
                                  and override only the options that are absolutely necessary.

                                  If you have a legitimate reason (as in, contractual obligations or
                                  whatnot) to require seperate hostnames, greetings, TLS settings and
                                  such, use the multi-instance features and seperate them. Otherwise the
                                  KISS principle applies.

                                  Cya,
                                  Jona
                                • Noel Jones
                                  ... You ve shared too much. By now no one has any idea what you re doing. Overview: Postscreen is a front-end listener for smtpd. It s not a proxy. Incoming
                                  Message 16 of 25 , Feb 21, 2013
                                  • 0 Attachment
                                    On 2/21/2013 10:46 AM, Erik Slagter wrote:
                                    > Another variation I tried ("pass" and "postscreen" the other way
                                    > around).


                                    You've shared too much. By now no one has any idea what you're doing.

                                    Overview:

                                    Postscreen is a front-end listener for smtpd. It's not a proxy.
                                    Incoming connections are handled by postscreen until postscreen
                                    either decides it's clean and passes the connection endpoint to
                                    smtpd, or rejected. This is covered in more detail in the
                                    POSTSCREEN_README.

                                    When postscreen decides to pass the connection to smtpd, postscreen
                                    is no longer involved, and smtpd has no knowledge of what transpired
                                    between postscreen and a client.


                                    Solution:

                                    [this is not a complete how-to, but will show you how to use
                                    multiple interfaces]

                                    At some point you reported:


                                    > mx1.ipv4.slagter.name:smtp inet n - n - 2 smtpd
                                    > -o myhostname=eriks.xs4all.nl
                                    > -o smtpd_banner=mx1.slagter.name-ESMTP-$mail_name-mx1-ppp0-ipv4-25
                                    > -o smtpd_tls_security_level=may

                                    Ok.

                                    > -o postscreen_tls_security_level=may
                                    > -o tlsproxy_tls_security_level=may

                                    both these belong in main.cf, or better, set main.cf:
                                    "smtpd_security_level = may" and leave these at their defaults.

                                    > -o smtpd_proxy_filter=nemesis.ipv4:10025
                                    > -o soft_bounce=no
                                    > -o postscreen_cache_map=btree:$data_directory/postscreen_cache-ipv4

                                    The cache map parameter belongs in main.cf. Probably a mistake to
                                    create separate caches.

                                    Same comments as above for the smtpd listener below.

                                    >
                                    > mx1.ipv6.slagter.name:smtp inet n - n - 2 smtpd
                                    > -o myhostname=mx1.ipv6.slagter.name
                                    > -o smtpd_banner=mx1.slagter.name-ESMTP-$mail_name-mx1-ppp0-ipv6-25
                                    > -o smtpd_tls_security_level=may
                                    > -o postscreen_tls_security_level=may
                                    > -o tlsproxy_tls_security_level=may
                                    > -o smtpd_proxy_filter=nemesis.ipv4:10025
                                    > -o soft_bounce=no
                                    > -o postscreen_cache_map=btree:$data_directory/postscreen_cache-ipv6



                                    For the TLS part, it will be much easier to turn TLS on in main.cf,
                                    then turn it off on the interfaces where you don't want to offer it
                                    with "-o smtpd_tls_security_level=none".

                                    # main.cf
                                    smtpd_tls_security_level = may

                                    For the greeting banners, set them as macros in main.cf and then
                                    refer to them by $name in master.cf

                                    # main.cf
                                    postscreen_greet_v4 = postscreen.v4.mx1 ESMTP greets you
                                    postscreen_greet_v6 = postscreen.v6.mx1 ESTMP greets you


                                    Now tell postscreen which ports to listen on and to enable the banner:

                                    # master.cf

                                    mx1.ipv4.slagter.name:smtp inet n - n - 1 postscreen
                                    -o postscreen_greet_banner=$postscreen_greet_v4

                                    mx1.ipv6.slagter.name:smtp inet n - n - 1 postscreen
                                    -o postscreen_greet_banner=$postscreen_greet_v6



                                    Next we tell smtpd to get it's connections from postscreen.
                                    On your existing "smtp ... smtpd" entries where you want postscreen,
                                    change the "smtp inet n" part to "smtp pass -"
                                    This is described in detail in
                                    http://www.postfix.org/POSTSCREEN_README.html#config

                                    so your existing entry:
                                    > mx1.ipv4.slagter.name:smtp inet n - n - 2 smtpd

                                    would become:
                                    mx1.ipv4.slagter.name:smtp pass - - n - 2 smtpd




                                    Good luck.



                                    -- Noel Jones
                                  • Erik Slagter
                                    ... Yes I blame the documentation, but not the software. I ve been using postfix for, well, something like ten years or more, I think it s the best thing since
                                    Message 17 of 25 , Feb 21, 2013
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                                      On 21-02-13 19:17, DTNX Postmaster wrote:

                                      > You keep blaming the documentation and the software, when the problem
                                      > is most likely in your understanding of it.

                                      Yes I blame the documentation, but not the software. I've been using
                                      postfix for, well, something like ten years or more, I think it's the
                                      best thing since sliced bread, especially compared to sendmail, qmail
                                      and exchange.

                                      The way I've configured it now, really suits the demands. I cannot
                                      remember any phrases in the documentation recommending not to do it this
                                      way (i.e. start multiple smtp listeners on different addresses with
                                      different options, in one master process). If it actually appears to be
                                      disrecommended, then that's clear to me, no problem.

                                      > Simplify your configuration. Don't assume that what goes for 'smtpd'
                                      > goes for 'postscreen' as well.

                                      I'd like to, but where do I find what I CAN assume? The factual
                                      documentation of postscreen is so sparse, it's mostly HOWTO,
                                      monkey-see-monkey-do.

                                      > Pick sensible defaults for 'main.cf',
                                      > and override only the options that are absolutely necessary.

                                      That's already done.

                                      > If you have a legitimate reason (as in, contractual obligations or
                                      > whatnot) to require seperate hostnames, greetings, TLS settings and
                                      > such, use the multi-instance features and seperate them. Otherwise the
                                      > KISS principle applies.

                                      Actually this way is much more KISS to me than running multiple
                                      instances of "master".

                                      I'm starting to think that the reason this operation is not documented,
                                      is because it's not possible. It looks like the postscreen layer
                                      literaly sits between the remote client and the smtp process, and the
                                      information where the connection took place (interface/address) is not
                                      available at the point where the smtpd is invoked.

                                      If that's the case, postscreen is not the way to go for me. I assumed
                                      postscreen was implemented a bit like proxy-filter, where you can run
                                      any number of filters on any number of addresses.
                                    • Erik Slagter
                                      ... I m just following the REPORT A PROBLEM procedure I was kindly pointed at... ... Yes at this point the smtpd/master has no knowledge of the
                                      Message 18 of 25 , Feb 21, 2013
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                                        On 21-02-13 19:30, Noel Jones wrote:

                                        > You've shared too much. By now no one has any idea what you're doing.

                                        I'm just following the "REPORT A PROBLEM" procedure I was kindly pointed
                                        at...

                                        > When postscreen decides to pass the connection to smtpd, postscreen
                                        > is no longer involved, and smtpd has no knowledge of what transpired
                                        > between postscreen and a client.

                                        Yes at this point the smtpd/master has no knowledge of the
                                        interface/address, that's exactly the thing I fear.

                                        > At some point you reported:
                                        > [ .. ]
                                        >> -o postscreen_tls_security_level=may
                                        >> -o tlsproxy_tls_security_level=may
                                        >
                                        > both these belong in main.cf, or better, set main.cf:
                                        > "smtpd_security_level = may" and leave these at their defaults.

                                        Tried both, doesn't matter. The thing is that what way you set the smtpd
                                        options (in main.cf) you cannot override them with postscreen. So if you
                                        set the default value suitable for address a and b, they must be
                                        override for address c and d and vv. Yes, I have some internal address
                                        that need to have tls_security=none and yes, that works like a charm
                                        without postscreen enabled.

                                        >> -o postscreen_cache_map=btree:$data_directory/postscreen_cache-ipv4
                                        >
                                        > The cache map parameter belongs in main.cf. Probably a mistake to
                                        > create separate caches.

                                        Nope, the cache map cannot be shared between two smtpd processes (see
                                        documentation ;-)). It's not a problem though, because one db holds ipv4
                                        addresses and the other is ipv6 addresses.

                                        > For the TLS part, it will be much easier to turn TLS on in main.cf,
                                        > then turn it off on the interfaces where you don't want to offer it
                                        > with "-o smtpd_tls_security_level=none".

                                        All relevant options for tls are actually set in main.cf. It's only that
                                        it's not enabled there, it's enabled on a per-address base. Which works.

                                        > For the greeting banners, set them as macros in main.cf and then
                                        > refer to them by $name in master.cf

                                        That's a possibility, but it's not necessary and doesn't solve the problem.

                                        > Now tell postscreen which ports to listen on and to enable the banner:
                                        >
                                        > # master.cf
                                        >
                                        > mx1.ipv4.slagter.name:smtp inet n - n - 1 postscreen
                                        > -o postscreen_greet_banner=$postscreen_greet_v4
                                        >
                                        > mx1.ipv6.slagter.name:smtp inet n - n - 1 postscreen
                                        > -o postscreen_greet_banner=$postscreen_greet_v6
                                        >
                                        > Next we tell smtpd to get it's connections from postscreen.
                                        > On your existing "smtp ... smtpd" entries where you want postscreen,
                                        > change the "smtp inet n" part to "smtp pass -"
                                        > This is described in detail in
                                        > http://www.postfix.org/POSTSCREEN_README.html#config
                                        >
                                        > so your existing entry:
                                        >> mx1.ipv4.slagter.name:smtp inet n - n - 2 smtpd
                                        >
                                        > would become:
                                        > mx1.ipv4.slagter.name:smtp pass - - n - 2 smtpd

                                        I get your drift, but IIRC I already tried this (multiple times, with
                                        slight variations) and also reported about the outcoming of that:
                                        "fatal: address already in use".

                                        Did I already mention I have followed all the steps from the README as
                                        closely as possible?
                                      • Viktor Dukhovni
                                        ... Take a DEEP breath, relax and don t *try* implementing new configurations you don t yet understand. The shots in the dark will just get you more confused.
                                        Message 19 of 25 , Feb 21, 2013
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                                          On Thu, Feb 21, 2013 at 05:46:26PM +0100, Erik Slagter wrote:

                                          > Another variation I tried ("pass" and "postscreen" the other way
                                          > around). This works, but gives the original problem, the smtpd
                                          > options are not honoured (especially banner and starttls="may"),
                                          > even though I set both:

                                          Take a DEEP breath, relax and don't *try* implementing new
                                          configurations you don't yet understand. The shots in the dark will
                                          just get you more confused.

                                          It is time to try to *understand*.

                                          1. A running Postfix instance is a collection of separate background
                                          services (daemons) launched by an inetd-like service supervisor known
                                          as "master. These services run independently in separate processes
                                          and communicate with each other using unix-domain sockets.

                                          They are configured either via main.cf (best practice) or via
                                          master.cf "-o parameter=$value" overrides (when you must).

                                          The MOST important thing you need to understand about this is:

                                          Adding "-o FOO=BAR" to the master.cf entry for SERVICEA has
                                          NO EFFECT on the value of FOO in SERVICEB!

                                          Even when the MESSAGE is passed from SERVICEA to SERVICEB the
                                          parameter settings ARE NOT.

                                          Thus when you convert an existing "smtpd" entry to a "postscreen"
                                          entry, it is a grave mistake to leave the "smtpd" (-o options)
                                          that tune the functionality of smtpd attached to the "postscreen"
                                          service. It (postscreen) won't care and the destination "smtpd"
                                          to which the message is handed off will no longer know the parameters.

                                          2. To provide multiple smtpd personalities, you need to implement multiple
                                          "smtpd" services each with their own settings. (As you do when smtpd
                                          listens directly on an "inet" socket).

                                          3. To implement 2. with postscreen, each "inet" listening postscreen
                                          (with settings relevant for postscreen) must hand the message off
                                          to an "smtpd" appropriate for its listening IP address.

                                          4. Therefore, you need multiple "smtpd" "pass" services for "postscreen"
                                          to hand the connection to. The postscreen(8) manual page refers you to

                                          http://www.postfix.org/postconf.5.html#smtpd_service_name

                                          which must specify the service name of a "pass" entry in master.cf,
                                          you need one of these for each distinct postscreen instance.

                                          192.0.2.1:25 inet ... postscreen
                                          -o smtpd_service_name=25@192.0.2.1
                                          -o <postscreen-related-settings> ...
                                          25@192.0.2.1 pass ... smtpd
                                          -o <smtpd-related-settings> ...

                                          Lather, rinse, repeat:

                                          192.0.2.1:587 inet ... postscreen
                                          -o smtpd_service_name=587@192.0.2.1
                                          -o <postscreen-related-settings> ...
                                          587@192.0.2.1 pass ... smtpd
                                          -o <smtpd-related-settings> ...

                                          Lather, rinse, repeat:

                                          192.0.2.2:25 inet ... postscreen
                                          -o smtpd_service_name=25@192.0.2.2
                                          -o <postscreen-related-settings> ...
                                          25@192.0.2.2 pass ... smtpd
                                          -o <smtpd-related-settings> ...

                                          Lather, rinse, repeat:

                                          192.0.2.3:25 inet ... postscreen
                                          -o smtpd_service_name=25@192.0.2.3
                                          -o <postscreen-related-settings> ...
                                          25@192.0.3.2 pass ... smtpd
                                          -o <smtpd-related-settings> ...

                                          ... but do stop eventually ... :-)

                                          --
                                          Viktor.
                                        • Erik Slagter
                                          ... And THAT is exactly the clue I was looking for! It works! The only thing that would have to be in the README file is the need to use smtpd service names
                                          Message 20 of 25 , Feb 22, 2013
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                                            On 21-02-13 20:07, Viktor Dukhovni wrote:

                                            > [ ... ] (lot of patronising text removed)

                                            > 4. Therefore, you need multiple "smtpd" "pass" services for "postscreen"
                                            > to hand the connection to. The postscreen(8) manual page refers you to
                                            >
                                            > http://www.postfix.org/postconf.5.html#smtpd_service_name
                                            >
                                            > which must specify the service name of a "pass" entry in master.cf,
                                            > you need one of these for each distinct postscreen instance.

                                            And THAT is exactly the clue I was looking for! It works!

                                            The only thing that would have to be in the README file is the need to
                                            use "smtpd service names" in case of multiple smtp listeners, point to
                                            http://www.postfix.org/postconf.5.html#smtpd_service_name and then add a
                                            bit of really helpful text to the current one:

                                            "The internal service that postscreen(8) hands off allowed connections
                                            to. In a future version there may be different classes of SMTP service."

                                            If you google for this command, you'll get references to either this
                                            text or this thread :-(

                                            So for other people seeking to do the same, this does the trick, it's
                                            also simple once you know, the "service" parameter of a "pass" service
                                            is not an address:portno combo but an identifier:

                                            #
                                            # outside -> inside
                                            # postfix(25) -> amavis(10025)
                                            #

                                            mx1.ipv4.slagter.name:smtp inet n - n - 1 postscreen
                                            -o postscreen_cache_map=btree:$data_directory/postscreen_cache-ipv4
                                            -o
                                            postscreen_greet_banner=mx1.slagter.name-ESMTP-mx1-postscreen-1-ppp0-ipv4-25
                                            -o smtpd_banner=mx1.slagter.name-ESMTP-mx1-postscreen-2-ppp0-ipv4-25
                                            -o postscreen_tls_security_level=none
                                            -o smtpd_service_name=mx1_ipv4

                                            mx1_ipv4 pass - - n - - smtpd
                                            -o myhostname=mx1.slagter.name
                                            -o smtpd_banner=mx1.slagter.name-ESMTP-$mail_name-mx1-ppp0-ipv4-25
                                            -o smtpd_tls_security_level=may
                                            -o smtpd_proxy_filter=nemesis.ipv4:10025 # amavis

                                            mx1.ipv6.slagter.name:smtp inet n - n - 1 postscreen
                                            -o postscreen_cache_map=btree:$data_directory/postscreen_cache-ipv6
                                            -o
                                            postscreen_greet_banner=mx1.slagter.name-ESMTP-mx1-postscreen-1-ppp0-ipv6-25
                                            -o smtpd_banner=mx1.slagter.name-ESMTP-mx1-postscreen-2-ppp0-ipv6-25
                                            -o postscreen_tls_security_level=none
                                            -o smtpd_service_name=mx1_ipv6

                                            mx1_ipv6 pass - - n - - smtpd
                                            -o myhostname=mx1.slagter.name
                                            -o smtpd_banner=mx1.slagter.name-ESMTP-$mail_name-mx1-ppp0-ipv6-25
                                            -o smtpd_tls_security_level=may
                                            -o smtpd_proxy_filter=nemesis.ipv4:10025 # amavis
                                          • Viktor Dukhovni
                                            On Fri, Feb 22, 2013 at 11:04:34AM +0100, Erik Slagter wrote: First, a quick comment, all of the sturm and drang in this thread is the result of a peculiar
                                            Message 21 of 25 , Feb 22, 2013
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                                              On Fri, Feb 22, 2013 at 11:04:34AM +0100, Erik Slagter wrote:

                                              First, a quick comment, all of the sturm and drang in this thread
                                              is the result of a peculiar reluctance of most users to heed the
                                              advice in MULTI_INSTANCE_README and simplify their configurations
                                              by handling each distinct message flow in a separate Postfix
                                              instance, each of which can be configured with few if any master.cf
                                              tweaks, and understood and maintained much more easily.

                                              A combination of MULTI_INSTANCE_README and POSTSCREEN_README would
                                              get you there much more quickly, and even allow simpler configuration
                                              of cases where identical policies apply to multiple protocol:address
                                              endpoints, since you can just set inet_interfaces in main.cf to list
                                              one or more network addresses for a given instance.

                                              I strongly recommend that you take the time to refactor your
                                              configuration to separate each flow into its own queue. The initial
                                              investment of time pays off quickly in easier to manage configurations
                                              and operational support (e.g. separate queues make it easier to
                                              see which flow is having problems).

                                              > On 21-02-13 20:07, Viktor Dukhovni wrote:
                                              >
                                              > > [ ... ] (lot of patronising text removed)

                                              Text that is required background knowledge to understand what
                                              follows, misconstrued to be patronizing rather than emphatic. Chill
                                              man, the blustery tone of this thread is mostly the result of your
                                              reticense to (AFAIK you never did) post the actual master.cf
                                              configuration that failed to meet your expectations. You should
                                              probably also not have included the text below in the initial post:

                                              The options (-o) that I specify on the various per-interface
                                              smtpd instances are NOT honoured anymore. ...

                                              Is this intentional? A know[n] bug? ...

                                              I must say the "howto" isn't very clear on this matter, it assumes you
                                              only have only one external interface.

                                              This is rude to the developers who take great pains to make Postfix
                                              unusually robust and well documented. The "patronising" text is
                                              sufficient to logically deduce that (and why) you need multiple
                                              smtpd "pass" services, at which point one looks for a parameter to
                                              specify the pass service, and finds it (in this case clustered
                                              sub-optimally with unrelated settings, we'll fix that) in the postscreen(8)
                                              manpage.

                                              If Wietse is still reading this, we should move "smtpd_service_name"
                                              to its ownn section nearer the top of the postscreen(8) manpage.

                                              Fortunately, the parameter name is just what you'd expect if you've
                                              ever seen "cleanup_service_name" which plays the same role one
                                              handoff downstream.

                                              > >4. Therefore, you need multiple "smtpd" "pass" services for "postscreen"
                                              > > to hand the connection to. The postscreen(8) manual page refers you to
                                              > >
                                              > > http://www.postfix.org/postconf.5.html#smtpd_service_name
                                              > >
                                              > > which must specify the service name of a "pass" entry in master.cf,
                                              > > you need one of these for each distinct postscreen instance.
                                              >
                                              > And THAT is exactly the clue I was looking for! It works!

                                              Naturally, since it is simply a logical consequence of understanding
                                              the patronising text. :-) Perhaps some people even spotted the
                                              transposition error in the last "Lather, rinse, repeat" example.
                                              (It has been observed that students pay more attention to technical
                                              books that contain minor errors that require them to pause and
                                              think, and that they learn more from these than from polished
                                              material that requires less attention).

                                              [
                                              Plus the fact that "unix" and "pass" service names are just file
                                              names in /var/spool/postfix/private/ which I started to describe
                                              in my first post, but decided to keep it more concise in the hope
                                              that this will be apparent from context.

                                              The master.cf services live in one of three namespaces:

                                              - inet/public (inet can't be private).

                                              - unix/public

                                              - unix/private

                                              Each of the "unix" cases subsumes "unix", "fifo" and "pass" since these
                                              all are accessed via paths in /var/spool/postfix/{public,private}.

                                              All delivery agents are "private" while "pickup", "qmgr", "flush"
                                              and "showq" are "public" to support postdrop(1) and postqueue(1)
                                              and their sendmail(1) interfaces. Almost everything else is private,
                                              except for cleanup(8) which AFAIK is public only for historical
                                              reasons.
                                              ]

                                              --
                                              Viktor.
                                            • Wietse Venema
                                              ... This was changed from private into public , so that postdrop could directly submit mail into cleanup, using the maildrop directory only as a fall-back
                                              Message 22 of 25 , Feb 22, 2013
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                                                Viktor Dukhovni:
                                                > All delivery agents are "private" while "pickup", "qmgr", "flush"
                                                > and "showq" are "public" to support postdrop(1) and postqueue(1)
                                                > and their sendmail(1) interfaces. Almost everything else is private,
                                                > except for cleanup(8) which AFAIK is public only for historical
                                                > reasons.

                                                This was changed from "private" into "public", so that postdrop
                                                could directly submit mail into cleanup, using the maildrop directory
                                                only as a fall-back mechanism in case cleanup transaction failed.
                                                Recovering from all possible failure modes is complicated and I did
                                                not get around to write that code (and there are few people who I
                                                would trust to write it).

                                                Wietse
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