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Re: Balancing destination concurrency + rate delay

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  • Robert Schetterer
    ... last time i had to do this , yahoo needs 3 weeks for whitelisting the new ip, used for a mail list server at the end if you already followed recommands for
    Message 1 of 11 , Jan 18, 2013
      Am 18.01.2013 18:49, schrieb Steve Jenkins:
      > Agreed - but Yahoo is really the only one we're having issues with (even
      > after complying with all their guidelines here)

      last time i had to do this , yahoo needs 3 weeks for whitelisting
      the new ip, used for a mail list server

      at the end if you already followed recommands for bulk mails on this
      list ( and archive ) with your mail server setup , there is less what
      you can do more, you may try more cascading (virtual)mailservers on
      other ips and/or more instances etc as well as other tricks
      but there is no magic ( beyond paying money ) to press someone accept
      your mail in timelimits you prefer, at last its not a question of
      postfix, its yahoos ( in this case ) decision


      Best Regards
      MfG Robert Schetterer

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    • Viktor Dukhovni
      ... Yes, they are willing to cripple SMTP and expect everyone to cope, because they are too big to ignore. :-) Rumour has it that established proffesional
      Message 2 of 11 , Jan 18, 2013
        On Fri, Jan 18, 2013 at 09:49:34AM -0800, Steve Jenkins wrote:

        > Agreed - but Yahoo is really the only one we're having issues with (even
        > after complying with all their guidelines here):
        >
        > http://help.yahoo.com/kb/index?page=content&y=PROD_MAIL_ML&locale=en_US&id=SLN3435
        >

        Yes, they are willing to cripple SMTP and expect everyone to cope,
        because they are too big to ignore. :-)

        Rumour has it that established proffesional bulk-senders typically
        don't turn up new IP addresses (no existing good reputation) to
        full capacity overnight. Rather, their sending software gradually
        ramps-up load to a new address allowing its reputation to build-up
        over time (the first few weeks may be at a low load, then add more,
        ...).

        Once your IP reputation is good, you should be able to use reasonable
        concurrency... You may want disable the demand connection cache
        for Yahoo. This cache is primarily useful for destinations that
        sporadically have some of their MX records unreachable at the TCP
        layer.

        Yahoo's MX SMTP pool essentially never has an IP address that is
        completely down. Instead, you can set a low "smtp_connect_timeout",
        just in case.

        master.cf:
        yahoo unix - - n - - smtp
        -o smtp_connect_timeout=$yahoo_connect_timeout
        -o smtp_connection_cache_on_demand=$yahoo_connection_cache_on_demand

        main.cf:
        # Good enough for light RTT to the moon
        yahoo_connect_timeout=3s

        # Don't annoy them with connection reuse.
        yahoo_connection_cache_on_demand=no

        At that point you may not even need rate delays, just set a modest
        concurrency, and typical SMTP transaction latency of 0.2-0.5s (
        with spam checks, RBL lookups, ...) will give you at most 2-5
        messages per unit concurrency per second.

        --
        Viktor.
      • Steve Jenkins
        On Fri, Jan 18, 2013 at 11:36 AM, Viktor Dukhovni
        Message 3 of 11 , Jan 18, 2013
          On Fri, Jan 18, 2013 at 11:36 AM, Viktor Dukhovni <postfix-users@...> wrote:
          Yes, they are willing to cripple SMTP and expect everyone to cope,
          because they are too big to ignore. :-)

          Sad, but true.
           
          At that point you may not even need rate delays, just set a modest
          concurrency, and typical SMTP transaction latency of 0.2-0.5s (
          with spam checks, RBL lookups, ...) will give you at most 2-5
          messages per unit concurrency per second.

          Would this be considered "modest?"

          yahoo_initial_destination_concurrency = 1
          yahoo_destination_concurrency_limit = 4
          yahoo_destination_recipient_limit = 2
          #yahoo_destination_rate_delay = 2s
          yahoo_connect_timeout=3s
          yahoo_connection_cache_on_demand=no

          Thx,

          SteveJ
           
        • Viktor Dukhovni
          ... You ll have to figure that out for yourself mostly, my gut reaction is that the recipient limit is too low, if you ever did have a multi-recipient message,
          Message 4 of 11 , Jan 18, 2013
            On Fri, Jan 18, 2013 at 07:46:45PM -0800, Steve Jenkins wrote:

            > > At that point you may not even need rate delays, just set a modest
            > > concurrency, and typical SMTP transaction latency of 0.2-0.5s (
            > > with spam checks, RBL lookups, ...) will give you at most 2-5
            > > messages per unit concurrency per second.
            > >
            >
            > Would this be considered "modest?"
            >
            > yahoo_initial_destination_concurrency = 1
            > yahoo_destination_concurrency_limit = 4
            > yahoo_destination_recipient_limit = 2
            > #yahoo_destination_rate_delay = 2s
            > yahoo_connect_timeout=3s
            > yahoo_connection_cache_on_demand=no

            You'll have to figure that out for yourself mostly, my gut reaction
            is that the recipient limit is too low, if you ever did have a
            multi-recipient message, you'd split it into too many pieces.
            Rather, set something in the 10-20 range (the RFC requires
            servers to support at least 100, and Postfix by default sends
            up to 50 and takes in up to 1000).

            After burning in your IP at low volume, with mail typically not
            delayed by Yahoo at all, I would try to grow the (destination aka
            connection) concurrency limit to something in the 5-10 range.

            The main thing that will matter is "burning in" a new IP address,
            once they've learned you're not evil, I would hope their rate limits
            won't get in your way at all.

            --
            Viktor.
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