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Re: Limit the number of messages sent per connection?

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  • S P Arif Sahari Wibowo
    ... Hmmm... I thought postfix only send 1 message per SMTP connection. -- (stephan paul) Arif Sahari Wibowo _____ _____ _____ _____ /____ /____/ /____/
    Message 1 of 6 , Mar 2, 2008
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      On Sun, 2 Mar 2008, Patrick Ben Koetter wrote:
      > Is there any parameter to control the maximum number of
      > messages per SMTP connection?

      Hmmm... I thought postfix only send 1 message per SMTP
      connection.

      --
      (stephan paul) Arif Sahari Wibowo
      _____ _____ _____ _____
      /____ /____/ /____/ /____
      _____/ / / / _____/ http://www.arifsaha.com/

      Xinnian Kuaile! 新年快樂 Gongxi Facai 恭喜發財
    • Ralf Hildebrandt
      ... Only in a distan, long gone past: http://www.postfix.org/CONNECTION_CACHE_README.html -- Ralf Hildebrandt (Ralf.Hildebrandt@charite.de)
      Message 2 of 6 , Mar 2, 2008
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        * S P Arif Sahari Wibowo <lists@...>:

        >> Is there any parameter to control the maximum number of messages per
        >> SMTP connection?
        >
        > Hmmm... I thought postfix only send 1 message per SMTP connection.

        Only in a distan, long gone past:
        http://www.postfix.org/CONNECTION_CACHE_README.html

        --
        Ralf Hildebrandt (Ralf.Hildebrandt@...) snickebo@...
        Postfix - Einrichtung, Betrieb und Wartung Tel. +49 (0)30-450 570-155
        http://www.arschkrebs.de
        Fat lady: I was Rubenesque before I was fat. --Metropolitan Museum of Art
      • S P Arif Sahari Wibowo
        ... Ah, that may explain all those emails to yahoo which ended up deferred. :-) So as the OP question, is there any way to limit this feature based on the
        Message 3 of 6 , Mar 2, 2008
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          On Sun, 2 Mar 2008, Ralf Hildebrandt wrote:
          > http://www.postfix.org/CONNECTION_CACHE_README.html

          Ah, that may explain all those emails to yahoo which ended up
          deferred. :-) So as the OP question, is there any way to limit
          this feature based on the number of message per connection, or
          turn off this feature entirely based on domain?

          --
          (stephan paul) Arif Sahari Wibowo
          _____ _____ _____ _____
          /____ /____/ /____/ /____
          _____/ / / / _____/ http://www.arifsaha.com/

          Xinnian Kuaile! 新年快樂 Gongxi Facai 恭喜發財
        • Noel Jones
          ... Postfix smtp connection caching is time based (how long can a connection stay active), not count based, so there is no control to limit the number of
          Message 4 of 6 , Mar 2, 2008
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            Patrick Ben Koetter wrote:
            > The Yahoo! guidelines for establishing SMTP connections to Yahoo! Mail require
            > a maximum of 5 messages per SMTP connection:
            >
            > "Are there any guidelines for establishing SMTP connections to Yahoo! Mail?"
            > <http://help.yahoo.com/l/us/yahoo/mail/postmaster/postmaster-277515.html>
            >
            > I know I can use a special default_destination_concurrency_limit to limit the
            > number of parallel connections (which is not what I need) and $max_use works
            > on incomming connections, but not on outgoing as it seems.
            >
            > Is there any parameter to control the maximum number of messages per SMTP
            > connection?
            >
            > p@rick
            >

            Postfix smtp connection caching is time based (how long can a
            connection stay active), not count based, so there is no
            control to limit the number of messages per connection to some
            arbitrary number.

            http://www.postfix.org/postconf.5.html#smtp_connection_cache_on_demand
            http://www.postfix.org/postconf.5.html#smtp_connection_cache_time_limit

            You can turn off connection caching for a specific transport
            in master.cf.

            abbreviated example:
            # transport
            yahoo.com nocache:

            # master.cf
            nocache unix - - n - - smtp
            -o smtp_connection_cache_on_demand=no

            --
            Noel Jones
          • Noel Jones
            ... After studying yahoo s instructions, it seems they don t intend to penalize you for attempting more than 5 messages per connection, they just disconnect
            Message 5 of 6 , Mar 2, 2008
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              Noel Jones wrote:
              > Patrick Ben Koetter wrote:
              >> The Yahoo! guidelines for establishing SMTP connections to Yahoo! Mail
              >> require
              >> a maximum of 5 messages per SMTP connection:
              >>
              >> "Are there any guidelines for establishing SMTP connections to
              >> Yahoo! Mail?"
              >>
              >> <http://help.yahoo.com/l/us/yahoo/mail/postmaster/postmaster-277515.html>
              >>
              >> I know I can use a special default_destination_concurrency_limit to
              >> limit the
              >> number of parallel connections (which is not what I need) and $max_use
              >> works
              >> on incomming connections, but not on outgoing as it seems.
              >>
              >> Is there any parameter to control the maximum number of messages per SMTP
              >> connection?
              >>
              >> p@rick
              >>
              >
              > Postfix smtp connection caching is time based (how long can a connection
              > stay active), not count based, so there is no control to limit the
              > number of messages per connection to some arbitrary number.
              >
              > http://www.postfix.org/postconf.5.html#smtp_connection_cache_on_demand
              > http://www.postfix.org/postconf.5.html#smtp_connection_cache_time_limit
              >
              > You can turn off connection caching for a specific transport in master.cf.
              >
              > abbreviated example:
              > # transport
              > yahoo.com nocache:
              >
              > # master.cf
              > nocache unix - - n - - smtp
              > -o smtp_connection_cache_on_demand=no
              >

              After studying yahoo's instructions, it seems they don't
              intend to penalize you for attempting more than 5 messages per
              connection, they just disconnect after the 5th and force you
              to make a new connection if you have more to say. They say in
              bold print:
              "Reestablish connections if you do not get an error code"

              If that's really what they are doing, Postfix should deal with
              it gracefully with no changes or special config.

              --
              Noel Jones
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