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Re: Trouble configuring backup MX to reject unauth destination

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  • Titanus Eramius
    Thinking about this, I might have been to specific in my question. At the fundamental level I would like to have 2 or more Postfix servers capable of receiving
    Message 1 of 28 , Feb 19 3:21 AM
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      Thinking about this, I might have been to specific in my question.

      At the fundamental level I would like to have 2 or more Postfix servers
      capable of receiving virtual mail for multiple domains, where one of
      the servers also handles relaying and local delivery. The rest should
      function as backup MX.

      I've tried with relay_domains, but it matches on domain-level which is
      too much. I then applied relay_recipient_maps, but it don't seem to
      have any effect, which means that addresses is still matched on domain
      basis.

      Every Postfix will have access to a complete list of recipients
      through MySQL.

      So the question becomes two-part:
      Why can't I get relay_recipient_maps to work?

      How would you recommend to set up a backup MX?
      One obvious way is not to do it, but some of the mail is not mine,
      which is why I at least would like the option to run a backup MX.
    • Viktor Dukhovni
      ... http://www.postfix.org/DEBUG_README.html#mail http://www.postfix.org/STANDARD_CONFIGURATION_README.html#backup Wildcard entries in canonical_maps and
      Message 2 of 28 , Feb 19 8:31 AM
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        On Tue, Feb 19, 2013 at 12:21:35PM +0100, Titanus Eramius wrote:

        > I've tried with relay_domains, but it matches on domain-level which is
        > too much. I then applied relay_recipient_maps, but it don't seem to
        > have any effect, which means that addresses is still matched on domain
        > basis.
        >
        > Every Postfix will have access to a complete list of recipients
        > through MySQL.
        >
        > So the question becomes two-part:
        > Why can't I get relay_recipient_maps to work?

        http://www.postfix.org/DEBUG_README.html#mail
        http://www.postfix.org/STANDARD_CONFIGURATION_README.html#backup

        Wildcard entries in canonical_maps and virtual_alias_maps are the
        most common reason for recipient validation failing to distinguish
        between valid and invalid recipients.

        --
        Viktor.
      • Titanus Eramius
        Tue, 19 Feb 2013 16:31:05 +0000 skrev Viktor Dukhovni ... Thank you for the response and sorry for the slow reply. The problem seems to be related with the
        Message 3 of 28 , Mar 22, 2013
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          Tue, 19 Feb 2013 16:31:05 +0000 skrev Viktor Dukhovni
          <postfix-users@...>:

          > On Tue, Feb 19, 2013 at 12:21:35PM +0100, Titanus Eramius wrote:
          >
          > > I've tried with relay_domains, but it matches on domain-level which
          > > is too much. I then applied relay_recipient_maps, but it don't seem
          > > to have any effect, which means that addresses is still matched on
          > > domain basis.
          > >
          > > Every Postfix will have access to a complete list of recipients
          > > through MySQL.
          > >
          > > So the question becomes two-part:
          > > Why can't I get relay_recipient_maps to work?
          >
          > http://www.postfix.org/DEBUG_README.html#mail
          > http://www.postfix.org/STANDARD_CONFIGURATION_README.html#backup
          >
          > Wildcard entries in canonical_maps and virtual_alias_maps are the
          > most common reason for recipient validation failing to distinguish
          > between valid and invalid recipients.
          >

          Thank you for the response and sorry for the slow reply.

          The problem seems to be related with the virtual setup, but I'm not
          sure how to best describe and document it.

          Besides aptget.dk this server also hosts cogky.dk (among others), and
          while unknown recipients is being correctly rejected with a 550 when
          sent to aptget.dk, they are not when sent to the other virtual domains.
          Instead they are accepted and then returned by the MAILER_DAEMON, which
          in turn opens the server to backscatter.

          I have tried setting "local_recipient_maps = $virtual_mailbox_maps"
          in main.cf, but without any apparent effect. To be honest, I'm unsure if
          I have set "virtual_mailbox_maps" correct, but when testing it with
          postalias it seems to work
          titanus@aptget:/etc/postfix$ sudo postalias -q titanus@...
          mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf
          aptget.dk/titanus/

          When I test mysql_virtual_mailbox_maps.cf with a non-existent address,
          nothing is returned and the exit status is 1.

          What I would like to achieve, is that Postfix rejects mail to
          non-existent recipients before accepting mail.

          Thanks again, Titanus


          postconf -n
          alias_maps = hash:/etc/aliases

          bounce_template_file = /etc/postfix/bounce.cf

          broken_sasl_auth_clients = yes

          config_directory = /etc/postfix

          delay_warning_time = 4

          disable_vrfy_command = yes

          dovecot_destination_recipient_limit = 1

          inet_interfaces = 46.21.105.38

          local_recipient_maps = $virtual_mailbox_maps

          mailman_destination_recipient_limit = 1

          maximal_queue_lifetime = 15

          message_size_limit = 26214400

          mydestination = localhost

          mydomain = aptget.dk

          myhostname = aptget.aptget.dk

          mynetworks = 127.0.0.0/8

          postscreen_dnsbl_action = enforce

          postscreen_dnsbl_sites = truncate.gbudb.net*2 b.barracudacentral.org*1
          zen.spamhaus.org*1 bl.spamcop.net*1

          postscreen_dnsbl_threshold = 2

          postscreen_greet_action = enforce

          recipient_canonical_classes = envelope_recipient

          recipient_canonical_maps = hash:/etc/postfix/pfix-no-srs.cf,
          tcp:127.0.0.1:10002

          sender_canonical_classes = envelope_sender

          sender_canonical_maps = hash:/etc/postfix/pfix-no-srs.cf,
          tcp:127.0.0.1:10001

          smtp_tls_security_level = may

          smtp_tls_session_cache_database =
          btree:$data_directory/smtp_tls_session_cache

          smtpd_data_restrictions = reject_unauth_pipelining,
          reject_multi_recipient_bounce,

          smtpd_helo_required = yes

          smtpd_recipient_restrictions = reject_non_fqdn_sender,
          reject_non_fqdn_recipient, reject_unknown_sender_domain,
          reject_unknown_recipient_domain, reject_unauth_destination,

          smtpd_sasl_auth_enable = yes

          smtpd_sasl_exceptions_networks = $mynetworks

          smtpd_sasl_path = private/auth

          smtpd_sasl_security_options = noanonymous

          smtpd_sasl_type = dovecot

          smtpd_tls_ask_ccert = yes

          smtpd_tls_cert_file = /etc/ssl/self-signed/smtpd.crt

          smtpd_tls_key_file = /etc/ssl/self-signed/smtpd.key

          smtpd_tls_loglevel = 1

          smtpd_tls_received_header = yes

          smtpd_tls_security_level = may

          smtpd_tls_session_cache_database =
          btree:$data_directory/smtpd_tls_session_cache

          spamassassin_destination_recipient_limit = 1

          tls_random_source = dev:/dev/urandom

          transport_maps = hash:/etc/postfix/transport.cf

          virtual_alias_maps =
          proxy:mysql:/etc/postfix/mysql_virtual_alias_maps.cf

          virtual_gid_maps = static:5000

          virtual_mailbox_base = /home/vmail

          virtual_mailbox_domains =
          proxy:mysql:/etc/postfix/mysql_virtual_domains_maps.cf

          virtual_mailbox_maps =
          proxy:mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf

          virtual_transport = dovecot

          virtual_uid_maps = static:5000
        • Wietse Venema
          ... Where is cogky.dk defined: mydestination, virtual_alias_domains, virtual_mailbox_domains, relay_domains? It must be only one. This answer determines where
          Message 4 of 28 , Mar 22, 2013
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            Titanus Eramius:
            > Besides aptget.dk this server also hosts cogky.dk (among others), and
            > while unknown recipients is being correctly rejected with a 550 when
            > sent to aptget.dk, they are not when sent to the other virtual domains.
            > Instead they are accepted and then returned by the MAILER_DAEMON, which
            > in turn opens the server to backscatter.

            Where is cogky.dk defined: mydestination, virtual_alias_domains,
            virtual_mailbox_domains, relay_domains? It must be only one.

            This answer determines where the "known" recipients must be listed:
            local_recipient_maps, virtual_alias_maps,m virtual_mailbox_maps,
            relay_recipients. If you list the domain or recipients in the wrong
            place then mail will be rejected.

            See http://www.postfix.org/ADDRESS_CLASS_README.html

            Wietse
          • Titanus Eramius
            Fri, 22 Mar 2013 16:55:21 -0400 (EDT) skrev Wietse Venema ... The goal is a virtual only mailserver, so the domains is stored in MySQL and fetched through
            Message 5 of 28 , Mar 22, 2013
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              Fri, 22 Mar 2013 16:55:21 -0400 (EDT) skrev Wietse Venema
              <wietse@...>:

              > Titanus Eramius:
              > > Besides aptget.dk this server also hosts cogky.dk (among others),
              > > and while unknown recipients is being correctly rejected with a 550
              > > when sent to aptget.dk, they are not when sent to the other virtual
              > > domains. Instead they are accepted and then returned by the
              > > MAILER_DAEMON, which in turn opens the server to backscatter.
              >
              > Where is cogky.dk defined: mydestination, virtual_alias_domains,
              > virtual_mailbox_domains, relay_domains? It must be only one.
              >
              > This answer determines where the "known" recipients must be listed:
              > local_recipient_maps, virtual_alias_maps,m virtual_mailbox_maps,
              > relay_recipients. If you list the domain or recipients in the wrong
              > place then mail will be rejected.
              >
              > See http://www.postfix.org/ADDRESS_CLASS_README.html
              >
              > Wietse

              The goal is a "virtual only" mailserver, so the domains is stored
              in MySQL and fetched through virtual_mailbox_domains. Besides
              virtual_mailbox_domains, I use virtual_mailbox_maps and
              virtual_alias_maps.

              The documentation is among the best documentation I have seen, but I
              can't seem to find the solution, even though I have read most of what I
              could find in relation to virtual handling.

              One more "clue" is the error messages when sending to non-existent
              users. When sending to aptget.dk Postfix responds with
              "550 5.1.1 <non_existent@...>: Recipient address rejected: User
              unknown in virtual mailbox table".

              When sending to cogky.dk the response is only "<non_existent@...>:
              user unknown"

              Thank you for your time, Titanus
            • Wietse Venema
              ... With the domain defined in virtual_mailbox_domains, mail will fail with user unknown in virtual mailbox table when the recipient is not found in
              Message 6 of 28 , Mar 22, 2013
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                Titanus Eramius:
                > Fri, 22 Mar 2013 16:55:21 -0400 (EDT) skrev Wietse Venema
                > > Where is cogky.dk defined: mydestination, virtual_alias_domains,
                > > virtual_mailbox_domains, relay_domains? It must be only one.
                > >
                > > This answer determines where the "known" recipients must be listed:
                > > local_recipient_maps, virtual_alias_maps,m virtual_mailbox_maps,
                > > relay_recipients. If you list the domain or recipients in the wrong
                > > place then mail will be rejected.
                > >
                > > See http://www.postfix.org/ADDRESS_CLASS_README.html
                >
                > The goal is a "virtual only" mailserver, so the domains is stored
                > in MySQL and fetched through virtual_mailbox_domains. Besides
                > virtual_mailbox_domains, I use virtual_mailbox_maps and
                > virtual_alias_maps.

                With the domain defined in virtual_mailbox_domains, mail will fail
                with "user unknown in virtual mailbox table" when the recipient is
                not found in virtual_mailbox_maps. This is described in agonizing
                detail in ADDRESS_CLASS_README.

                Test your lookups:

                postmap -q cogky.dk the-virtual_mailbox_domains-table
                This should return a result (the value does not matter).

                postmap -q real-user@... the-virtual_mailbox_maps-table
                This should return a result (the mailbox file name).

                postmap -q bogus-user@... the-virtual_mailbox_maps-table
                This should return no result (Postfix treats this as "user unknown
                in virtual mailbox table").

                Wietse
              • mouss
                ... one possible reason is that you configured a wildcard alias: @cogky.dk == @aptget.dk (that is anything to cogky maps to same address in aptget.dk). if so,
                Message 7 of 28 , Mar 24, 2013
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                  Le 23/03/2013 00:02, Titanus Eramius a écrit :
                  > [snip]
                  > The goal is a "virtual only" mailserver, so the domains is stored
                  > in MySQL and fetched through virtual_mailbox_domains. Besides
                  > virtual_mailbox_domains, I use virtual_mailbox_maps and
                  > virtual_alias_maps.
                  >
                  > The documentation is among the best documentation I have seen, but I
                  > can't seem to find the solution, even though I have read most of what I
                  > could find in relation to virtual handling.
                  >
                  > One more "clue" is the error messages when sending to non-existent
                  > users. When sending to aptget.dk Postfix responds with
                  > "550 5.1.1 <non_existent@...>: Recipient address rejected: User
                  > unknown in virtual mailbox table".
                  >
                  > When sending to cogky.dk the response is only "<non_existent@...>:
                  > user unknown"
                  >

                  one possible reason is that you configured a wildcard alias:
                  @... ==> @...
                  (that is anything to cogky maps to same address in aptget.dk).

                  if so, that's your problem. you need to configure mappings only for
                  existing users.
                  since you use mysql, this should be easy to do.
                • Titanus Eramius
                  Fri, 22 Mar 2013 19:12:40 -0400 (EDT) skrev Wietse Venema ... aptget:~# postalias -q cogky.dk mysql:/etc/postfix/mysql_virtual_mailbox_domains.cf cogky.dk ...
                  Message 8 of 28 , Mar 25, 2013
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                    Fri, 22 Mar 2013 19:12:40 -0400 (EDT) skrev Wietse Venema
                    <wietse@...>:

                    > Test your lookups:
                    >
                    > postmap -q cogky.dk the-virtual_mailbox_domains-table
                    > This should return a result (the value does not matter).

                    aptget:~# postalias -q cogky.dk
                    mysql:/etc/postfix/mysql_virtual_mailbox_domains.cf
                    cogky.dk

                    > postmap -q real-user@... the-virtual_mailbox_maps-table
                    > This should return a result (the mailbox file name).

                    aptget:~# postalias -q real-user@...
                    mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf
                    cogky.dk/real-user/

                    > postmap -q bogus-user@... the-virtual_mailbox_maps-table
                    > This should return no result (Postfix treats this as "user unknown
                    > in virtual mailbox table").

                    And this does not return a result. Bash gives a error-status of 1.


                    Sun, 24 Mar 2013 09:36:03 +0100 skrev mouss <mouss@...>:

                    > one possible reason is that you configured a wildcard alias:
                    > @... ==> @...
                    > (that is anything to cogky maps to same address in aptget.dk).

                    As far as I can see that should not be the case. All addresses and
                    aliases in the database have a left hand side to it. Is there a way to
                    test this?


                    I'm using Dovecot 2 as LDA for final delivery and IMAP-services, so
                    "virtual_transport" is set to "dovecot" in main.cf and the following
                    lines are in master.cf:

                    dovecot unix - n n - - pipe
                    flags=DRhu user=vmail:vmail argv=/usr/lib/dovecot/deliver -d
                    ${recipient}


                    When looking through the log, it looks like the "user unknown"
                    response comes from Dovecot and not Postfix:

                    Mar 25 13:43:53 aptget postfix/smtpd[24133]: connect from
                    unknown[92.243.255.38]

                    Mar 25 13:43:54 aptget postfix/smtpd[24133]:
                    Anonymous TLS connection established from unknown[92.243.255.38]: TLSv1
                    with cipher DHE-RSA-AES128-SHA (128/128 bits)

                    Mar 25 13:43:54 aptget dovecot: auth-worker(24136): mysql(localhost):
                    Connected to database postfix

                    Mar 25 13:43:54 aptget postfix/smtpd[24133]: BB6AD371DDC4:
                    client=unknown[92.243.255.38], sasl_method=LOGIN,
                    sasl_username=HIDDEN_USER@...

                    Mar 25 13:43:54 aptget postfix-policyd: connection from: 127.0.0.1
                    port: 48937 slots: 0 of 4096 used

                    Mar 25 13:43:54 aptget postfix-policyd: connecting to mysql database:
                    localhost

                    Mar 25 13:43:54 aptget postfix-policyd: connected..

                    Mar 25 13:43:54 aptget postfix-policyd: rcpt=16, throttle=clear(a),
                    host=92.243.255.38, from=titanus@..., to=unknown-user@...,
                    size=365/26214400, quota=365/1800000000, count=1/125(10),
                    rcpt=1/600(11), threshold=0%|0%|0%, sasl_username=HIDDEN_USER@...

                    Mar 25 13:43:54 aptget postfix/cleanup[24138]: BB6AD371DDC4:
                    message-id=<20130325134351.5c2e026f@...>

                    Mar 25 13:43:54 aptget postfix/qmgr[23982]: BB6AD371DDC4:
                    from=<titanus@...>, size=663, nrcpt=1 (queue active)

                    Mar 25 13:43:55 aptget postfix/pipe[24140]: BB6AD371DDC4:
                    to=<unknown-user@...>, relay=dovecot, delay=0.38,
                    delays=0.26/0.03/0/0.09, dsn=5.1.1, status=bounced (user unknown)

                    Mar 25 13:43:55 aptget postfix/cleanup[24138]: 16228371DE3E:
                    message-id=<20130325124355.16228371DE3E@...>

                    Mar 25 13:43:55 aptget postfix/bounce[24142]: BB6AD371DDC4: sender
                    non-delivery notification: 16228371DE3E

                    Mar 25 13:43:55 aptget postfix/qmgr[23982]: 16228371DE3E: from=<>,
                    size=2673, nrcpt=1 (queue active)

                    Mar 25 13:43:55 aptget postfix/qmgr[23982]: BB6AD371DDC4: removed

                    Mar 25 13:43:55 aptget postfix/smtpd[24133]: disconnect from
                    unknown[92.243.255.38]


                    Thank you again for helping
                    Titanus


                    postconf -n
                    alias_maps = hash:/etc/aliases

                    bounce_template_file = /etc/postfix/bounce.cf

                    broken_sasl_auth_clients = yes

                    config_directory = /etc/postfix

                    delay_warning_time = 4

                    disable_vrfy_command = yes

                    dovecot_destination_recipient_limit = 1

                    inet_interfaces = 46.21.105.38

                    local_recipient_maps = $virtual_mailbox_maps

                    mailman_destination_recipient_limit = 1

                    maximal_queue_lifetime = 15

                    message_size_limit = 26214400

                    mydestination = localhost

                    mydomain = aptget.dk

                    myhostname = aptget.aptget.dk

                    mynetworks = 127.0.0.0/8

                    postscreen_dnsbl_action = enforce
                    postscreen_dnsbl_sites = truncate.gbudb.net*2 b.barracudacentral.org*1
                    zen.spamhaus.org*1 bl.spamcop.net*1

                    postscreen_dnsbl_threshold = 2

                    postscreen_greet_action = enforce

                    recipient_canonical_classes = envelope_recipient

                    recipient_canonical_maps = hash:/etc/postfix/pfix-no-srs.cf,
                    tcp:127.0.0.1:10002

                    sender_canonical_classes = envelope_sender

                    sender_canonical_maps = hash:/etc/postfix/pfix-no-srs.cf,
                    tcp:127.0.0.1:10001

                    smtp_tls_security_level = may

                    smtp_tls_session_cache_database =
                    btree:$data_directory/smtp_tls_session_cache

                    smtpd_data_restrictions = reject_unauth_pipelining,
                    reject_multi_recipient_bounce,

                    smtpd_helo_required = yes

                    smtpd_recipient_restrictions = reject_non_fqdn_sender,
                    reject_non_fqdn_recipient, reject_unknown_sender_domain,
                    reject_unknown_recipient_domain, reject_unauth_destination,

                    smtpd_sasl_auth_enable = yes

                    smtpd_sasl_exceptions_networks = $mynetworks

                    smtpd_sasl_path = private/auth

                    smtpd_sasl_security_options = noanonymous

                    smtpd_sasl_type = dovecot

                    smtpd_tls_ask_ccert = yes

                    smtpd_tls_cert_file = /etc/ssl/self-signed/smtpd.crt

                    smtpd_tls_key_file = /etc/ssl/self-signed/smtpd.key

                    smtpd_tls_loglevel = 1

                    smtpd_tls_received_header = yes

                    smtpd_tls_security_level = may

                    smtpd_tls_session_cache_database =
                    btree:$data_directory/smtpd_tls_session_cache

                    spamassassin_destination_recipient_limit = 1

                    tls_random_source = dev:/dev/urandom

                    transport_maps = hash:/etc/postfix/transport.cf

                    virtual_alias_maps =
                    proxy:mysql:/etc/postfix/mysql_virtual_alias_maps.cf

                    virtual_gid_maps = static:5000

                    virtual_mailbox_base = /home/vmail

                    virtual_mailbox_domains =
                    proxy:mysql:/etc/postfix/mysql_virtual_domains_maps.cf

                    virtual_mailbox_maps =
                    proxy:mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf

                    virtual_transport = dovecot

                    virtual_uid_maps = static:5000
                  • Wietse Venema
                    ... OK, the table is working as it should. Now let s find out why the bogus recipient is accepted: Next step: - Connect to the public (not content
                    Message 9 of 28 , Mar 25, 2013
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                      Titanus Eramius:
                      > Fri, 22 Mar 2013 19:12:40 -0400 (EDT) skrev Wietse Venema
                      > <wietse@...>:
                      >
                      > > Test your lookups:
                      > >
                      > > postmap -q cogky.dk the-virtual_mailbox_domains-table
                      > > This should return a result (the value does not matter).
                      >
                      > aptget:~# postalias -q cogky.dk
                      > mysql:/etc/postfix/mysql_virtual_mailbox_domains.cf
                      > cogky.dk
                      >
                      > > postmap -q real-user@... the-virtual_mailbox_maps-table
                      > > This should return a result (the mailbox file name).
                      >
                      > aptget:~# postalias -q real-user@...
                      > mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf
                      > cogky.dk/real-user/
                      >
                      > > postmap -q bogus-user@... the-virtual_mailbox_maps-table
                      > > This should return no result (Postfix treats this as "user unknown
                      > > in virtual mailbox table").
                      >
                      > And this does not return a result. Bash gives a error-status of 1.

                      OK, the table is working as it should. Now let's find out
                      why the bogus recipient is accepted:

                      Next step:

                      - Connect to the public (not content re-injection) SMTP port and try

                      $ telnet hostname 25
                      ehlo ...
                      mail from:<>
                      rcpt to:<real-user@...>
                      rcpt to:<bogus-user@...>
                      quit

                      One recipient should be accepted, the other not.

                      - Same experiment for mail over the submission port, if you have one:

                      $ openssl s_client -starttls smtp -connect hostname:587
                      ehlo ...
                      mail from:<>
                      rcpt to:<real-user@...>
                      rcpt to:<bogus-user@...>
                      quit

                      This is just in case.

                      Wietse
                    • Titanus Eramius
                      Mon, 25 Mar 2013 11:30:41 -0400 (EDT) skrev Wietse Venema ... Both RCPT TOs are successful titanus@asrock:~$ telnet 46.21.105.38 25 Trying 46.21.105.38...
                      Message 10 of 28 , Mar 25, 2013
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                        Mon, 25 Mar 2013 11:30:41 -0400 (EDT) skrev Wietse Venema
                        <wietse@...>:

                        > Titanus Eramius:
                        > > Fri, 22 Mar 2013 19:12:40 -0400 (EDT) skrev Wietse Venema
                        > > <wietse@...>:
                        > >
                        > > > Test your lookups:
                        > > >
                        > > > postmap -q cogky.dk the-virtual_mailbox_domains-table
                        > > > This should return a result (the value does not matter).
                        > >
                        > > aptget:~# postalias -q cogky.dk
                        > > mysql:/etc/postfix/mysql_virtual_mailbox_domains.cf
                        > > cogky.dk
                        > >
                        > > > postmap -q real-user@... the-virtual_mailbox_maps-table
                        > > > This should return a result (the mailbox file name).
                        > >
                        > > aptget:~# postalias -q real-user@...
                        > > mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf
                        > > cogky.dk/real-user/
                        > >
                        > > > postmap -q bogus-user@... the-virtual_mailbox_maps-table
                        > > > This should return no result (Postfix treats this as "user unknown
                        > > > in virtual mailbox table").
                        > >
                        > > And this does not return a result. Bash gives a error-status of 1.
                        >
                        > OK, the table is working as it should. Now let's find out
                        > why the bogus recipient is accepted:
                        >
                        > Next step:
                        >
                        > - Connect to the public (not content re-injection) SMTP port and try
                        >
                        > $ telnet hostname 25
                        > ehlo ...
                        > mail from:<>
                        > rcpt to:<real-user@...>
                        > rcpt to:<bogus-user@...>
                        > quit
                        >
                        > One recipient should be accepted, the other not.
                        >
                        > - Same experiment for mail over the submission port, if you have one:
                        >
                        > $ openssl s_client -starttls smtp -connect hostname:587
                        > ehlo ...
                        > mail from:<>
                        > rcpt to:<real-user@...>
                        > rcpt to:<bogus-user@...>
                        > quit
                        >
                        > This is just in case.
                        >
                        > Wietse

                        Both RCPT TOs are successful

                        titanus@asrock:~$ telnet 46.21.105.38 25
                        Trying 46.21.105.38...
                        Connected to 46.21.105.38.
                        Escape character is '^]'.
                        220 aptget.aptget.dk ESMTP Postfix
                        EHLO Hej
                        250-aptget.aptget.dk
                        250-PIPELINING
                        250-SIZE 26214400
                        250-ETRN
                        250-STARTTLS
                        250-AUTH PLAIN LOGIN
                        250-AUTH=PLAIN LOGIN
                        250-ENHANCEDSTATUSCODES
                        250-8BITMIME
                        250 DSN
                        MAIL FROM:<>
                        250 2.1.0 Ok
                        RCPT TO:<real-user@...>
                        250 2.1.5 Ok
                        RCPT TO:<non-existent@...>
                        250 2.1.5 Ok
                        QUIT
                        221 2.0.0 Bye
                        Connection closed by foreign host.

                        If non-existent@... is substituted with non-existent@...,
                        then it is still rejected with "... unknown in virtual mailbox table".

                        When trying with submission through telnet, I'm afraid I can't get the
                        syntax right. But when using the mail client Claws Mail, Postfix
                        accepts non-existent addresses for cogky.dk

                        ...
                        [17:51:52] ESMTP< 235 2.7.0 Authentication successful
                        [17:51:52] ESMTP> MAIL FROM:<nicky@...> SIZE=371
                        [17:51:52] SMTP< 250 2.1.0 Ok
                        [17:51:52] SMTP> RCPT TO:<non-existent@...>
                        [17:51:52] SMTP< 250 2.1.5 Ok
                        ...

                        Thank you, Titanus
                      • Wietse Venema
                        ... You appear to have a wild-card rule that replaces @cogky.dk with @aptget.dk. Such a rule matches all addresses including invalid ones. Instead use a MySQL
                        Message 11 of 28 , Mar 25, 2013
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                          Titanus Eramius:
                          > > OK, the table is working as it should. Now let's find out
                          > > why the bogus recipient is accepted:
                          > >
                          > > Next step:
                          > >
                          > > - Connect to the public (not content re-injection) SMTP port and try
                          ...
                          > MAIL FROM:<>
                          > 250 2.1.0 Ok
                          > RCPT TO:<real-user@...>
                          > 250 2.1.5 Ok
                          > RCPT TO:<non-existent@...>
                          > 250 2.1.5 Ok

                          > If non-existent@... is substituted with non-existent@...,
                          > then it is still rejected with "... unknown in virtual mailbox table".

                          You appear to have a wild-card rule that replaces @... with
                          @.... Such a rule matches all addresses including invalid ones.

                          Instead use a MySQL query as decribed in
                          http://tech.groups.yahoo.com/group/postfix-users/message/247913

                          Wietse
                        • Titanus Eramius
                          Mon, 25 Mar 2013 14:09:04 -0400 (EDT) skrev Wietse Venema ... Thank you for the link, it was very informative, but didn t solve the problem. I also tried
                          Message 12 of 28 , Apr 5, 2013
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                            Mon, 25 Mar 2013 14:09:04 -0400 (EDT) skrev Wietse Venema
                            <wietse@...>:

                            > Titanus Eramius:

                            > > MAIL FROM:<>
                            > > 250 2.1.0 Ok
                            > > RCPT TO:<real-user@...>
                            > > 250 2.1.5 Ok
                            > > RCPT TO:<non-existent@...>
                            > > 250 2.1.5 Ok
                            >
                            > > If non-existent@... is substituted with non-existent@...,
                            > > then it is still rejected with "... unknown in virtual mailbox
                            > > table".
                            >
                            > You appear to have a wild-card rule that replaces @... with
                            > @.... Such a rule matches all addresses including invalid ones.
                            >
                            > Instead use a MySQL query as decribed in
                            > http://tech.groups.yahoo.com/group/postfix-users/message/247913
                            >
                            > Wietse

                            Thank you for the link, it was very informative, but didn't solve the
                            problem. I also tried making a virtual_mailbox_maps MySQL query that
                            always returned false, but Postfix still accepted all mail, and then
                            bounced it after Dovecot rejected it.

                            I have converted virtual_mailbox_maps and virtual_mailbox_domains to
                            textfiles, so it should be easier to debug on the setup. Please note
                            that I had to change server to experiment like this, since I depend
                            on the other server.

                            The servername is nt-data.dk, and the hosted domain (which all mail is
                            accepted for) is nt-backup.dk. The behavior is the same, so mail sent
                            to non_existent@... is rejected, while mail sent to
                            non_existent@... is accepted, and then bounced.

                            In main.cf (please see the bottom for postconf -n) is
                            virtual_mailbox_domains =
                            hash:/etc/postfix/virtual_mailbox_domains.cf
                            virtual_mailbox_maps =
                            hash:/etc/postfix/virtual_mailbox_maps.cf

                            And the content of those files is
                            virtual_mailbox_domains.cf:
                            nt-backup.dk OK
                            nt-data.dk OK

                            virtual_mailbox_maps.cf:
                            test@... OK
                            info@... OK

                            It all works like a charm, besides the point that Postfix accepts
                            mail to non-existent users on the hosted domain.

                            In addition I have read through the relevant documentation again, but I
                            still can't figure out where or what the problem might be.

                            Thanks again


                            postconf -n
                            alias_maps = hash:/etc/aliases

                            bounce_template_file = /etc/postfix/bounce.cf

                            broken_sasl_auth_clients = yes

                            config_directory = /etc/postfix

                            delay_warning_time = 4

                            disable_vrfy_command = yes

                            inet_interfaces = all

                            local_recipient_maps = $virtual_mailbox_maps

                            maximal_queue_lifetime = 15

                            mydestination =

                            myhostname = ntdata.nt-data.dk

                            mynetworks = 127.0.0.0/8

                            recipient_canonical_classes = envelope_recipient

                            recipient_canonical_maps = hash:/etc/postfix/pfix-no-srs.cf,
                            tcp:127.0.0.1:10002

                            sender_canonical_classes = envelope_sender

                            sender_canonical_maps = hash:/etc/postfix/pfix-no-srs.cf,
                            tcp:127.0.0.1:10001

                            smtp_tls_security_level = may

                            smtp_tls_session_cache_database =
                            btree:$data_directory/smtp_tls_session_cache

                            smtpd_data_restrictions =
                            reject_unauth_pipelining,
                            reject_multi_recipient_bounce,
                            permit

                            smtpd_helo_required = yes

                            smtpd_recipient_restrictions =
                            reject_non_fqdn_sender,
                            reject_non_fqdn_recipient,
                            reject_unknown_sender_domain,
                            reject_unknown_recipient_domain,
                            reject_rbl_client truncate.gbudb.net,
                            reject_unauth_destination,
                            permit

                            smtpd_sasl_auth_enable = yes

                            smtpd_sasl_exceptions_networks = $mynetworks

                            smtpd_sasl_path = private/auth

                            smtpd_sasl_security_options = noanonymous

                            smtpd_sasl_type = dovecot

                            smtpd_tls_ask_ccert = yes

                            smtpd_tls_cert_file = /etc/ssl/self-signed/smtpd.crt

                            smtpd_tls_key_file = /etc/ssl/self-signed/smtpd.key

                            smtpd_tls_loglevel = 1

                            smtpd_tls_received_header = yes

                            smtpd_tls_security_level = may

                            smtpd_tls_session_cache_database =
                            btree:$data_directory/smtpd_tls_session_cache

                            tls_random_source = dev:/dev/urandom

                            transport_maps = hash:/etc/postfix/transport.cf

                            virtual_mailbox_domains = hash:/etc/postfix/virtual_mailbox_domains.cf

                            virtual_mailbox_maps = hash:/etc/postfix/virtual_mailbox_maps.cf

                            virtual_transport = dovecot
                          • Brian Evans
                            ... You say you return false ? Postfix expects to receive no results (a.k.a. 0 rows) if a virtual_mailbox_maps address in mysql does not exist. Do not return
                            Message 13 of 28 , Apr 5, 2013
                            • 0 Attachment
                              On 4/5/2013 6:56 AM, Titanus Eramius wrote:
                              > Mon, 25 Mar 2013 14:09:04 -0400 (EDT) skrev Wietse Venema
                              > <wietse@...>:
                              >
                              >> Titanus Eramius:
                              >>> MAIL FROM:<>
                              >>> 250 2.1.0 Ok
                              >>> RCPT TO:<real-user@...>
                              >>> 250 2.1.5 Ok
                              >>> RCPT TO:<non-existent@...>
                              >>> 250 2.1.5 Ok
                              >>> If non-existent@... is substituted with non-existent@...,
                              >>> then it is still rejected with "... unknown in virtual mailbox
                              >>> table".
                              >> You appear to have a wild-card rule that replaces @... with
                              >> @.... Such a rule matches all addresses including invalid ones.
                              >>
                              >> Instead use a MySQL query as decribed in
                              >> http://tech.groups.yahoo.com/group/postfix-users/message/247913
                              >>
                              >> Wietse
                              > Thank you for the link, it was very informative, but didn't solve the
                              > problem. I also tried making a virtual_mailbox_maps MySQL query that
                              > always returned false, but Postfix still accepted all mail, and then
                              > bounced it after Dovecot rejected it.

                              You say you return "false"?
                              Postfix expects to receive no results (a.k.a. 0 rows) if a
                              virtual_mailbox_maps address in mysql does not exist.
                              Do not return "false", empty string, null, or any other value if it does
                              not exist.

                              Brian
                            • Titanus Eramius
                              Fri, 05 Apr 2013 08:49:39 -0400 skrev Brian Evans ... False may be the wrong word, and I m sorry if it is. What I mean is, virtual_mailbox_maps always returns
                              Message 14 of 28 , Apr 5, 2013
                              • 0 Attachment
                                Fri, 05 Apr 2013 08:49:39 -0400 skrev Brian Evans
                                <grknight@...>:

                                > > Thank you for the link, it was very informative, but didn't solve
                                > > the problem. I also tried making a virtual_mailbox_maps MySQL query
                                > > that always returned false, but Postfix still accepted all mail,
                                > > and then bounced it after Dovecot rejected it.
                                >
                                > You say you return "false"?
                                > Postfix expects to receive no results (a.k.a. 0 rows) if a
                                > virtual_mailbox_maps address in mysql does not exist.
                                > Do not return "false", empty string, null, or any other value if it
                                > does not exist.

                                False may be the wrong word, and I'm sorry if it is. What I mean is,
                                virtual_mailbox_maps always returns nothing from MySQL, like so:

                                titanus@ntdata:/etc/postfix$ sudo postmap -q test@...
                                mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf
                                titanus@ntdata:/etc/postfix$ echo $?
                                1
                                (this user exists)

                                titanus@ntdata:/etc/postfix$ sudo postmap -q non_existent@...
                                mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf
                                titanus@ntdata:/etc/postfix$ echo $?
                                1
                                (this user does not)

                                I did this because I had some trouble constructing the query-string
                                Wietse recommended, and thought this would be a simple and easy way to
                                test if virtual_mailbox_maps was the problem.

                                When trying the syntax within the MySQL CLI, a "Empty set" is returned
                                when querying for a non-existent user

                                mysql> SELECT username FROM mailbox
                                -> WHERE username = 'non_existent@...';
                                Empty set (0.00 sec)


                                I hope this better explains what I meant
                                Cheers
                              • Titanus Eramius
                                Solved it :-) When sending to unknown users, Postfix now rejects the mail with User unknown in virtual mailbox table , and it does so for hosted (that is,
                                Message 15 of 28 , Apr 6, 2013
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                                  Solved it :-)

                                  When sending to unknown users, Postfix now rejects the mail with "User
                                  unknown in virtual mailbox table", and it does so for hosted (that is,
                                  virtual mailbox domains) domains as well.

                                  It seems the SRS-daemon* I have been using with the main.cf parameters
                                  recipient_canonical_maps
                                  recipient_canonical_classes
                                  sender_canonical_maps
                                  sender_canonical_classes

                                  was the root of the problem. I have just commented them out to solve
                                  it. Reading through the documentation for those four parameters, does
                                  not seem to indicate why they would mess with Postfix' ability to use
                                  virtual_mailbox_maps.

                                  But I guess my lack of understanding about Postfix internals is a
                                  problem as well. I am sorry for the wasted time, and would like to
                                  thank all who helped out.

                                  Have a nice weekend


                                  * https://github.com/Fruneau/pfixtools
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