[Mailman-Users] Mail stuck in Exim queue

Adrian Cooper adrian at cooper.net
Sat Oct 30 13:57:39 CEST 2004

Hi John,

> On 10/29/2004 16:20, "Adrian Cooper" <adrian at cooper.net> wrote:
> > There does seem to be a problem with Exim accepting the Mailman
> > speed.
> Not here, but CPanel isn't involved here.

cPanel is not really an issue since the O/S level installations are the same
or similar.

The solution appears to be to restrict the number of concurrent connections
between Mailman and Exim. I have added the relevant lines to the Mailman
configuration but for some reason if I place the recommended line in
Exim.conf, Exim will not start. The line is:

smtp_max_sessions_per_connection = 30

No one on the Exim list seem to know what the problem is with this.

This is the relevant information as documented in:


And it is nothing to do with cPanel:

By default Mailman will send up to 500 recipients on each message it injects
into exim. However this is not necessarily a good configuration for exim
since it will route all those recipients before starting deliveries to any
of them. Additionally some ACL configurations have tests on the maximum
number of recipients (which is a good reason for having a get out ACL for
list traffic as described above)
I would suggest setting Mailman to send a maximum of 5 to 50 recipients on a
single mail (setting it lower decreases list latency, but increases the work
that Mailman and exim have to do), and change it to send a maximum of 30
messages per SMTP connection. To reflect this you should also change the
exim parameter smtp_accept_queue_per_connection to be 30 as well.

For example, add the following lines to ~mailman/Mailman/mm_cfg.py:

  # Max recipients for each message
  # Max messages sent in each SMTP connection

So the problem clearly exists according to both Exim and Mailman, and is not
a cPanel thing.

Any suggestions would be most welcome!



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