[Mailman-Users] Outgoing qrunner stops working and outgoing mails get stuck

[SP]

Hi everybody.

Since a couple of months I have started having some problems with
mailman. Sometimes it stops sending out e-mail: outgoing messages get
stuck in ~/qfiles/out.

The qrunner for outgoing mail is up and running, but it simply does not
process the messages in the queue. Restarting mailman, or simply sending
a SIGHUP at the Outgoing qrunner solves the problem: immediately mailman
starts handling the messages in the queue and processes *all of them*
without any problem.

And then, after some time (sometimes a week, sometimes a couple of days)
again it stops.

I checked the mailman logs, but I can't find any error or any message
that can help debugging the problem...

I am running mailman 2.1.9 on Fedora, with qmail as MTA and python 2.4.3.

I have really drained all my ideas... any suggestion, of any kind will
be appreciated!

Thank you,

Paso