Possible Bug: Under high load schleuder does not process X-COMMANDS correctly
This is some strange behaviour I just encountered.
If loads of mail (>1000 in this case) are thrown at a schleuder installation, schleuder does not process x-resend-enc.
we just got hit by a spamming attack, which our mailserver recognized as such, stopped it, but produced an error mail for each spam message. those are send to the admins via ... a schleuder list. so the load on the server was quite high :)
when i send a mail via a different schleuder on the same server in this situation, x-resend-enc is ignored. as far as i can tell it was just sending the mail to the list members.
there is no indication of a malfunction (in the pseudo header or in the logfile) - its just like the x-resend-enc wasn't there - and the pseudo header reflects that: there is no note that the mail was resend, that is simply missing.
if the load goes down to "normal" again, the same mail (send again) gets processed as expected.
the server/vm in question has 1 gig main memory, debian stable. there is no indication of an out-of-memory situation.
i try to find out some more on this, but maybe somebody has seen this before.