Bug#297915: exim4: Mail duplicated

[Johan Thelmén]

torsdagen den 3 mars 2005 15.27 skrev John Goerzen:
> Package: exim4
> Version: 4.34-10
> Severity: normal
> 
> I am using the exiscan support for spamassassin.
> 
> I am having trouble with exim4 delivering duplicated copies of messages.
> Spamassassin is giving me trouble, using 40+ minutes of CPU time to
> process some messages, but I would think that exim4 should be more
> resilient in the face of this.
> 
> It seems that remote hosts for some reason believe the message did not
> get delivered, even though it did, and try repeatedly to re-send it.

If processing a message take more then one minute you should find out why
spamassassin is taking so long. The server sending the message to exim have
to wait until spamassassin is complete before it send the final OK accepted
for delivery from exim. This time have to less then ten minutes set by the
SMTP RFC standard. If it take longer the sending server think there is
something wrong and will dissconnect and retry later without exim knowing.
That way exim will deliver the message and the other server try again.

In reality some people is not even following the RFC standard and I have seen
this same problem on some messages that only take over 90seconds to scan.
I changed to a faster server and the problem went away.

Maybe you are not limiting size of mails you are scanning with spamassassin.

I have this before the spamcheck that is the last check.

 # Do not spamcheck mail over 150K when overloaded
  accept
        condition       = ${if >{$message_size}{150k}{1}{0}}
        condition       = ${if >{$load_average}{900}{1}{0}}
  # Do not spamcheck mail over 2M when we have other work to do
  accept
        condition       = ${if >{$message_size}{2m}{1}{0}}
        condition       = ${if >{$load_average}{70}{1}{0}}

Good luck.

-- 
Johan Thelmen
Falun Sweden