Loading ...
Sorry, an error occurred while loading the content.

Re: Trouble configuring backup MX to reject unauth destination

Expand Messages
  • /dev/rob0
    ... pickup(8) picks up mail which was sent via sendmail(1). This is a local/system user s process (UID 5005, specifically) sending the mail. Your
    Message 1 of 28 , Feb 8, 2013
    • 0 Attachment
      On Fri, Feb 08, 2013 at 04:06:57PM +0100, Titanus Eramius wrote:
      > Please note that the last time I asked about the behavior of Postfix it
      > turned out I had misunderstood the concept of relaying mail. It might
      > be the case again.
      >
      > I'm running the mailserver that serves this domain + a few others,
      > the mailserver at ubuntudanmark.dk and the mailservers at nt-data.dk.
      >
      > So I'm running these servers, with this relation:
      > mx01.aptget.dk <-- Not a backup MX
      > mx01.ubuntudanmark.dk <-- Not a backup MX
      > mx01.nt-data.dk <-- Backup MX for mx01.aptget.dk and
      > mx01.ubuntudanmark.dk
      > mx02.nt-data.dk <-- Backup MX for mx01.nt-data.dk
      >
      > The setup is entirely virtual, using MySQL to store aliases, addressees
      > etc. The problem is, that *I think* the backup MX' can be used to
      > spread backscatter. I routinely looks at the Postfix logging, and found
      > these entries yesterday from mx01.nt-data.dk:
      >
      > ---
      > titanus@ntdata:/var/log$ grep "048341743609" mail.log.1
      >
      > Feb 7 22:12:48 ntdata postfix/pickup[24843]: 048341743609: uid=5005
      > from=<SRS0=3u76=L7=gmail.com=jimmiedcu949@...>

      pickup(8) picks up mail which was sent via sendmail(1). This is a
      local/system user's process (UID 5005, specifically) sending the
      mail. Your misunderstanding this time seems to be that you think it
      came from the network and could thus be rejected.

      If this seems to be some kind of abuse, it could be that something
      you're running on the server has been compromised; web/php scripts
      being the most common vector.

      > Feb 7 22:12:48 ntdata postfix/cleanup[30176]: 048341743609:
      > message-id=<GI63Z8-USKQ93-NH@...>
      >
      > Feb 7 22:12:48 ntdata postfix/qmgr[20252]: 048341743609:
      > from=<SRS0=3u76=L7=gmail.com=jimmiedcu949@...>, size=5268,
      > nrcpt=1 (queue active)
      >
      > Feb 7 22:12:48 ntdata postfix/smtp[30181]: 048341743609:
      > to=<acer@...>,
      > relay=mx01.ubuntudanmark.dk[31.192.231.5]:25, delay=0.71,
      > delays=0/0.04/0.17/0.5, dsn=5.1.1, status=bounced (host
      > mx01.ubuntudanmark.dk[31.192.231.5] said: 550 5.1.1
      > <acer@...>: Recipient address rejected: User unknown in
      > virtual mailbox table (in reply to RCPT TO command))
      >
      > Feb 7 22:12:48 ntdata postfix/bounce[30182]: 048341743609: sender
      > non-delivery notification: B201D1743608
      >
      > Feb 7 22:12:48 ntdata postfix/qmgr[20252]: 048341743609: removed
      > ---
      >
      > Then mx01.nt-data.dk tries to send a bounce to gmail:
      >
      > ---
      > Feb 7 22:12:52 ntdata postfix/smtp[30183]: B201D1743608:
      > to=<jimmiedcu949@...>,
      > orig_to=<SRS0=3u76=L7=gmail.com=jimmiedcu949@...>,

      Here you have virtually aliased this sender (now a bounce recipient)
      address to jimmiedcu949@....

      > relay=gmail-smtp-in.l.google.com[173.194.71.26]:25, delay=3.4,
      > delays=0.01/0.01/0.29/3, dsn=5.1.1, status=bounced (host
      > gmail-smtp-in.l.google.com[173.194.71.26] said: 550-5.1.1 The email
      > account that you tried to reach does not exist. Please try 550-5.1.1
      > double-checking the recipient's email address for typos or 550-5.1.1
      > unnecessary spaces. Learn more at 550 5.1.1
      > http://support.google.com/mail/bin/answer.py?answer=6596
      > bc7si9536557lbb.184 - gsmtp (in reply to RCPT TO command))
      > ---
      >
      > The address acer@... does not exist - Neither at
      > mx01.nt-data.dk nor at mx01.ubuntudanmark.dk, so I would like
      > mx01.nt-data.dk to reject messages to it. I've tried with other
      > non-existent addresses trough telnet, and mx01.nt-data.dk accepts them,
      > as long as they are to one of the backup domains, and then bounces them
      > (so currently they are disabled in the database).

      There is no possible mechanism within Postfix to reject mail
      submitted via the sendmail command.

      > Following is postconf -n, the content of the 2 relay_* MySQL-files, and
      > the structure of their database. If more is needed, then please let me
      > know and I'll include it.
      >
      > Any pointers, examples or explanations will be appreciated. I've read
      > in the documentation for virtual hosting and backup MX', but the answer
      > seems to evades me.

      FWIW, generally a backup MX is a bad idea. Why did you want it?

      [snip]
      --
      http://rob0.nodns4.us/ -- system administration and consulting
      Offlist GMX mail is seen only if "/dev/rob0" is in the Subject:
    • Titanus Eramius
      Fri, 8 Feb 2013 09:45:07 -0600 skrev /dev/rob0 : snip ... I m sorry, UID 5005 is SpamAssassin. The grep-command didn t got all ... Feb 7
      Message 2 of 28 , Feb 8, 2013
      • 0 Attachment
        Fri, 8 Feb 2013 09:45:07 -0600 skrev /dev/rob0 <rob0@...>:

        snip
        > > ---
        > > titanus@ntdata:/var/log$ grep "048341743609" mail.log.1
        > >
        > > Feb 7 22:12:48 ntdata postfix/pickup[24843]: 048341743609: uid=5005
        > > from=<SRS0=3u76=L7=gmail.com=jimmiedcu949@...>
        >
        > pickup(8) picks up mail which was sent via sendmail(1). This is a
        > local/system user's process (UID 5005, specifically) sending the
        > mail. Your misunderstanding this time seems to be that you think it
        > came from the network and could thus be rejected.
        >
        > If this seems to be some kind of abuse, it could be that something
        > you're running on the server has been compromised; web/php scripts
        > being the most common vector.

        I'm sorry, UID 5005 is SpamAssassin. The grep-command didn't got all
        the lines, so here they are:
        ---
        Feb 7 22:12:46 ntdata postfix/smtpd[30171]: connect from
        c-50-151-186-224.hsd1.in.comcast.net[50.151.186.224]

        Feb 7 22:12:47 ntdata postfix/smtpd[30171]: 39E441743607:
        client=c-50-151-186-224.hsd1.in.comcast.net[50.151.186.224]

        Feb 7 22:12:47 ntdata postfix/cleanup[30176]: 39E441743607:
        message-id=<GI63Z8-USKQ93-NH@...>

        Feb 7 22:12:47 ntdata postfix/qmgr[20252]: 39E441743607:
        from=<SRS0=3u76=L7=gmail.com=jimmiedcu949@...>, size=2182,
        nrcpt=1 (queue active)

        Feb 7 22:12:47 ntdata spamd[6887]: spamd: connection from
        localhost.localdomain [127.0.0.1] at port 58896 Feb 7 22:12:47 ntdata
        spamd[6887]: spamd: processing message
        <GI63Z8-USKQ93-NH@...> for
        acer@...:5005

        Feb 7 22:12:47 ntdata postfix/smtpd[30171]:
        disconnect from c-50-151-186-224.hsd1.in.comcast.net[50.151.186.224]

        Feb 7 22:12:48 ntdata spamd[6887]: spamd: identified spam (11.6/5.0)
        for acer@...:5005 in 0.4 seconds, 2200 bytes.

        Feb 7 22:12:48 ntdata spamd[6887]: spamd: result: Y 11 -
        FH_HELO_EQ_D_D_D_D,HELO_DYNAMIC_IPADDR,RCVD_IN_BRBL_LASTEXT,RCVD_IN_PBL,RCVD_IN_XBL,RDNS_DYNAMIC,SPF_FAIL
        scantime=0.4,size=2200,user=acer@...,uid=5005,required_score=5.0,rhost=localhost.localdomain,raddr=127.0.0.1,rport=58896,mid=<GI63Z8-USKQ93-NH@...>,autolearn=no

        Feb 7 22:12:48 ntdata postfix/pickup[24843]: 048341743609: uid=5005
        from=<SRS0=3u76=L7=gmail.com=jimmiedcu949@...>

        Feb 7 22:12:48 ntdata postfix/pipe[30177]: 39E441743607:
        to=<acer@...>, relay=spamassassin, delay=0.95,
        delays=0.53/0/0/0.41, dsn=2.0.0, status=sent (delivered via
        spamassassin service)

        Feb 7 22:12:48 ntdata postfix/qmgr[20252]: 39E441743607: removed

        Feb 7 22:12:48 ntdata postfix/cleanup[30176]: 048341743609:
        message-id=<GI63Z8-USKQ93-NH@...>

        Feb 7 22:12:48 ntdata postfix/qmgr[20252]: 048341743609:
        from=<SRS0=3u76=L7=gmail.com=jimmiedcu949@...>, size=5268,
        nrcpt=1 (queue active)

        Feb 7 22:12:48 ntdata spamd[6886]: prefork: child states: II

        Feb 7 22:12:48 ntdata postfix/smtp[30181]: certificate verification
        failed for mx01.ubuntudanmark.dk[31.192.231.5]:25: self-signed
        certificate

        Feb 7 22:12:48 ntdata postfix/smtp[30181]: 048341743609:
        to=<acer@...>,
        relay=mx01.ubuntudanmark.dk[31.192.231.5]:25, delay=0.71,
        delays=0/0.04/0.17/0.5, dsn=5.1.1, status=bounced (host
        mx01.ubuntudanmark.dk[31.192.231.5] said: 550 5.1.1
        <acer@...>: Recipient address rejected: User unknown in
        virtual mailbox table (in reply to RCPT TO command))

        Feb 7 22:12:48 ntdata postfix/cleanup[30176]: B201D1743608:
        message-id=<20130207211248.B201D1743608@...-data.dk>

        Feb 7 22:12:48 ntdata postfix/bounce[30182]: 048341743609: sender
        non-delivery notification: B201D1743608

        Feb 7 22:12:48 ntdata postfix/qmgr[20252]: B201D1743608: from=<>,
        size=7699, nrcpt=1 (queue active)

        Feb 7 22:12:48 ntdata postfix/qmgr[20252]: 048341743609: removed

        Feb 7 22:12:49 ntdata postfix/smtp[30183]: certificate verification
        failed for gmail-smtp-in.l.google.com[173.194.71.26]:25: untrusted
        issuer /C=US/O=Equifax/OU=Equifax Secure Certificate Authority

        Feb 7 22:12:52 ntdata postfix/smtp[30183]: B201D1743608:
        to=<jimmiedcu949@...>,
        orig_to=<SRS0=3u76=L7=gmail.com=jimmiedcu949@...>,
        relay=gmail-smtp-in.l.google.com[173.194.71.26]:25, delay=3.4,
        delays=0.01/0.01/0.29/3, dsn=5.1.1, status=bounced (host
        gmail-smtp-in.l.google.com[173.194.71.26] said: 550-5.1.1 The email
        account that you tried to reach does not exist. Please try 550-5.1.1
        double-checking the recipient's email address for typos or 550-5.1.1
        unnecessary spaces. Learn more at 550 5.1.1
        http://support.google.com/mail/bin/answer.py?answer=6596
        bc7si9536557lbb.184 - gsmtp (in reply to RCPT TO command))

        Feb 7 22:12:52 ntdata postfix/qmgr[20252]: B201D1743608: removed
        ---

        snip

        >
        > FWIW, generally a backup MX is a bad idea. Why did you want it?
        >
        > [snip]

        Yeah, I start to see why. nt-data is my (soon to be) hosting company,
        and when handling other peoples mail, I think it's wise to have some
        sort of a backup system in place.

        I've been searching high and low for alternatives, but short of setting
        something fancy up there don't seem to be any.

        Thank you for the reply.
      • Jeroen Geilman
        ... So you are...not re-injecting spamassassin traffic, but instead re-submitting it via sendmail ? That s weird. ... THIS is a send to spamassassin, but
        Message 3 of 28 , Feb 8, 2013
        • 0 Attachment
          On 02/08/2013 06:02 PM, Titanus Eramius wrote:

          > Feb 7 22:12:48 ntdata postfix/pickup[24843]: 048341743609: uid=5005
          > from=<SRS0=3u76=L7=gmail.com=jimmiedcu949@...>

          So you are...not re-injecting spamassassin traffic, but instead
          re-submitting it via sendmail ?
          That's weird.

          > Feb 7 22:12:48 ntdata postfix/pipe[30177]: 39E441743607:
          > to=<acer@...>, relay=spamassassin, delay=0.95,
          > delays=0.53/0/0/0.41, dsn=2.0.0, status=sent (delivered via
          > spamassassin service)

          THIS is a send to spamassassin, but delayed in logging for almost a second.

          It looks very much as if you're doing in-line spamassassin checks, but
          then not re-injecting it via SMTP.

          Why are you doing such a strange thing ?


          --
          J.
        • Titanus Eramius
          ... To be honest I ve read quite a lot about Postfix, Dovecot, SA ... , but my experience is very limited and contained to about 3 months of running time. So
          Message 4 of 28 , Feb 9, 2013
          • 0 Attachment
            Fri, 08 Feb 2013 21:54:02 +0100 skrev Jeroen Geilman <jeroen@...>:

            > On 02/08/2013 06:02 PM, Titanus Eramius wrote:
            >
            > > Feb 7 22:12:48 ntdata postfix/pickup[24843]: 048341743609: uid=5005
            > > from=<SRS0=3u76=L7=gmail.com=jimmiedcu949@...>
            >
            > So you are...not re-injecting spamassassin traffic, but instead
            > re-submitting it via sendmail ?
            > That's weird.
            >
            > > Feb 7 22:12:48 ntdata postfix/pipe[30177]: 39E441743607:
            > > to=<acer@...>, relay=spamassassin, delay=0.95,
            > > delays=0.53/0/0/0.41, dsn=2.0.0, status=sent (delivered via
            > > spamassassin service)
            >
            > THIS is a send to spamassassin, but delayed in logging for almost a
            > second.
            >
            > It looks very much as if you're doing in-line spamassassin checks,
            > but then not re-injecting it via SMTP.
            >
            > Why are you doing such a strange thing ?
            >

            To be honest I've read quite a lot about Postfix, Dovecot, SA ... , but
            my experience is very limited and contained to about 3 months of
            running time.

            So SA is integrated as I found best after reading docs and guides, and
            it's more than likely it can be done in a better way. Normally though,
            the running time of SA is around ~200ms per text-mail.

            It's integrated as a content_filter on smtp like so:
            smtp inet n - - - - smtpd -o content_filter=spamassassin

            And then on it's own lines:
            spamassassin unix - n n - - pipe
            flags=Rq user=spamd argv=/usr/bin/spamc -u ${user}@${domain}
            -e /usr/sbin/sendmail -oi -f ${sender} ${recipient}

            The sendmail-method seems to be preferred by the SA-folks
            https://wiki.apache.org/spamassassin/IntegratedSpamdInPostfix

            All of those examples uses sendmail. But again, in relation to Postfix,
            it might very well be possible to integrate SA in a better way. Maybe
            the method suggested by the docs on content_filters?
            http://www.postfix.org/FILTER_README.html#advanced_filter
          • James Griffin
            ... Integrating SA with amavisd-new is a better approach IMO. You might consider that in your setup? -- Primary Key: 4096R/1D31DC38 2011-12-03 Key Fingerprint:
            Message 5 of 28 , Feb 9, 2013
            • 0 Attachment
              --> Titanus Eramius <titanus@...> [2013-02-09 12:23:38 +0100]:

              > All of those examples uses sendmail. But again, in relation to Postfix,
              > it might very well be possible to integrate SA in a better way. Maybe
              > the method suggested by the docs on content_filters?
              > http://www.postfix.org/FILTER_README.html#advanced_filter

              Integrating SA with amavisd-new is a better approach IMO. You might
              consider that in your setup?

              --
              Primary Key: 4096R/1D31DC38 2011-12-03
              Key Fingerprint: A4B9 E875 A18C 6E11 F46D B788 BEE6 1251 1D31 DC38
            • Noel Jones
              ... Nothing wrong with this setup. It s very easy to configure, requires no third-party software or additional packages, and it s easy to understand where
              Message 6 of 28 , Feb 9, 2013
              • 0 Attachment
                On 2/9/2013 5:23 AM, Titanus Eramius wrote:
                > Fri, 08 Feb 2013 21:54:02 +0100 skrev Jeroen Geilman <jeroen@...>:
                >
                >> On 02/08/2013 06:02 PM, Titanus Eramius wrote:
                >>
                >>> Feb 7 22:12:48 ntdata postfix/pickup[24843]: 048341743609: uid=5005
                >>> from=<SRS0=3u76=L7=gmail.com=jimmiedcu949@...>
                >>
                >> So you are...not re-injecting spamassassin traffic, but instead
                >> re-submitting it via sendmail ?
                >> That's weird.
                >>
                >>> Feb 7 22:12:48 ntdata postfix/pipe[30177]: 39E441743607:
                >>> to=<acer@...>, relay=spamassassin, delay=0.95,
                >>> delays=0.53/0/0/0.41, dsn=2.0.0, status=sent (delivered via
                >>> spamassassin service)
                >>
                >> THIS is a send to spamassassin, but delayed in logging for almost a
                >> second.
                >>
                >> It looks very much as if you're doing in-line spamassassin checks,
                >> but then not re-injecting it via SMTP.
                >>
                >> Why are you doing such a strange thing ?
                >>
                >
                > To be honest I've read quite a lot about Postfix, Dovecot, SA ... , but
                > my experience is very limited and contained to about 3 months of
                > running time.
                >
                > So SA is integrated as I found best after reading docs and guides, and
                > it's more than likely it can be done in a better way. Normally though,
                > the running time of SA is around ~200ms per text-mail.
                >
                > It's integrated as a content_filter on smtp like so:
                > smtp inet n - - - - smtpd -o content_filter=spamassassin
                >
                > And then on it's own lines:
                > spamassassin unix - n n - - pipe
                > flags=Rq user=spamd argv=/usr/bin/spamc -u ${user}@${domain}
                > -e /usr/sbin/sendmail -oi -f ${sender} ${recipient}
                >
                > The sendmail-method seems to be preferred by the SA-folks
                > https://wiki.apache.org/spamassassin/IntegratedSpamdInPostfix
                >
                > All of those examples uses sendmail. But again, in relation to Postfix,
                > it might very well be possible to integrate SA in a better way.

                Nothing wrong with this setup. It's very easy to configure,
                requires no third-party software or additional packages, and it's
                easy to understand where your mail goes. I expect that's why it's
                used as an example on the spamassassin wiki, and doesn't necessarily
                mean it's the recommended or preferred method.

                It's not necessarily the highest performance or the most flexible,
                but if it suits your needs, no need to change.

                Folks who need more usually pick some third-party filtering software
                that can run pre-queue as an smtpd_proxy_filter or milter. These
                are, without exception, more complicated than the setup you
                currently have. The big advantage of a pre-queue filter is you can
                safely REJECT unwanted mail.

                Amavisd-new is a popular choice for pre-queue filtering since it's
                fast, reliable, flexible, and can integrate both SpamAssassin and
                antivirus.


                -- Noel Jones
              • Titanus Eramius
                Sat, 09 Feb 2013 10:25:31 -0600 skrev Noel Jones : ... Sorry for the late response, it took some time to dig through all the
                Message 7 of 28 , Feb 16, 2013
                • 0 Attachment
                  Sat, 09 Feb 2013 10:25:31 -0600 skrev Noel Jones
                  <njones@...>:

                  ...

                  > Nothing wrong with this setup. It's very easy to configure,
                  > requires no third-party software or additional packages, and it's
                  > easy to understand where your mail goes. I expect that's why it's
                  > used as an example on the spamassassin wiki, and doesn't necessarily
                  > mean it's the recommended or preferred method.
                  >
                  > It's not necessarily the highest performance or the most flexible,
                  > but if it suits your needs, no need to change.
                  >
                  > Folks who need more usually pick some third-party filtering software
                  > that can run pre-queue as an smtpd_proxy_filter or milter. These
                  > are, without exception, more complicated than the setup you
                  > currently have. The big advantage of a pre-queue filter is you can
                  > safely REJECT unwanted mail.
                  >
                  > Amavisd-new is a popular choice for pre-queue filtering since it's
                  > fast, reliable, flexible, and can integrate both SpamAssassin and
                  > antivirus.
                  >
                  >
                  > -- Noel Jones

                  Sorry for the late response, it took some time to dig through all the
                  information. The use of pre-queue filtering would solve another problem
                  I've been working on: What to do with mail from (user)blacklisted
                  senders.

                  I plan on upgrading Debians stable Postfix to the current stable
                  version of 2.10 so I may benefit from postscreen, and that will
                  probably be a good time to install amavisd-new as a pre-queue filter.

                  Thank you for the help once again.
                • DTNX Postmaster
                  ... A possible shortcut to getting postscreen is using the 2.9.3 version available in the Debian backports repository. That s what we currently use, instead of
                  Message 8 of 28 , Feb 16, 2013
                  • 0 Attachment
                    On Feb 16, 2013, at 12:18, Titanus Eramius <titanus@...> wrote:

                    > I plan on upgrading Debians stable Postfix to the current stable
                    > version of 2.10 so I may benefit from postscreen, and that will
                    > probably be a good time to install amavisd-new as a pre-queue filter.
                    >
                    > Thank you for the help once again.

                    A possible shortcut to getting postscreen is using the 2.9.3 version
                    available in the Debian backports repository. That's what we currently
                    use, instead of building custom packages.

                    HTH,
                    Jona
                  • Titanus Eramius
                    Sat, 16 Feb 2013 12:39:24 +0100 skrev DTNX Postmaster ... Thank you for pointing the obvious out. I don t know why I didn t thought of backports, but I will
                    Message 9 of 28 , Feb 16, 2013
                    • 0 Attachment
                      Sat, 16 Feb 2013 12:39:24 +0100 skrev DTNX Postmaster
                      <postmaster@...>:

                      > On Feb 16, 2013, at 12:18, Titanus Eramius <titanus@...> wrote:
                      >
                      > > I plan on upgrading Debians stable Postfix to the current stable
                      > > version of 2.10 so I may benefit from postscreen, and that will
                      > > probably be a good time to install amavisd-new as a pre-queue
                      > > filter.
                      > >
                      > > Thank you for the help once again.
                      >
                      > A possible shortcut to getting postscreen is using the 2.9.3 version
                      > available in the Debian backports repository. That's what we
                      > currently use, instead of building custom packages.
                      >
                      > HTH,
                      > Jona
                      >

                      Thank you for pointing the obvious out.
                      I don't know why I didn't thought of backports, but I will surely be
                      using 2.9.3 from there instead of building from source.
                    • 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 10 of 28 , Feb 19, 2013
                      • 0 Attachment
                        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 11 of 28 , Feb 19, 2013
                        • 0 Attachment
                          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 12 of 28 , Mar 22, 2013
                          • 0 Attachment
                            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 13 of 28 , Mar 22, 2013
                            • 0 Attachment
                              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 14 of 28 , Mar 22, 2013
                              • 0 Attachment
                                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 15 of 28 , Mar 22, 2013
                                • 0 Attachment
                                  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 16 of 28 , Mar 24, 2013
                                  • 0 Attachment
                                    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 17 of 28 , Mar 25, 2013
                                    • 0 Attachment
                                      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 18 of 28 , Mar 25, 2013
                                      • 0 Attachment
                                        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 19 of 28 , Mar 25, 2013
                                        • 0 Attachment
                                          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 20 of 28 , Mar 25, 2013
                                          • 0 Attachment
                                            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 21 of 28 , Apr 5, 2013
                                            • 0 Attachment
                                              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 22 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 23 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 24 of 28 , Apr 6, 2013
                                                  • 0 Attachment
                                                    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
                                                  Your message has been successfully submitted and would be delivered to recipients shortly.