[Mailman-Users] Fwd: Mailing list lag to SOME users

[Stephen J. Turnbull]

Kevin Carpenter writes:

 > We have documented cases of two users at the same company having 
 > dramatically different delivery times.  e.g.  for user1 at abc.com and 
 > user2 at abc.com:  user2 may get delivery in 5 seconds vs. user1 getting 
 > the delivery in 4 hours, inconsistently.  e.g. the next message may go 
 > through fine, or delay a different user.

Sounds like greylisting to me.

 > Lets try the headers a different way: http://puu.sh/aZpeO/cbef0bd773.png

Your DNS may be problematic.  The PTR for the address of "mail" points
to "spoe".  For most protocols, a CNAME is good enough, but SMTP wants
the MX to have an A record, and many receiving hosts will look at the
failure of mail --A--> x.y.z.w --PTR--> spoe to roundtrip mail --> mail
and label that incoming connection as "possibly forged".  I don't know
if anybody takes that very seriously these days, but you might want to
change that PTR to point to "mail" rather than "spoe".  Be careful:
that PTR may be there for a reason.  I don't think this has anything
to do with the issue at hand, though.

I guess amavis is configured to accept mail via LMTP on port 10024
(lines 4, 7), and to inject mail via LMTP (thus the host is not
identified beyond "unknown" in lines 5,8) on the default port.

Mailman appears to be the recipient at line 5, and reinjecting at line
6.  But line 6 is your external address for "spoe".

The important information is between lines 5 and 6.  In mailman's logs
(post, smtp, error, etc), check for Mailman activity on this post at
09:57, and also for SMTP activity.  Since Mailman is sending to your
external address, if grey listing is active, it would show up here as
two attempts to send, one at 09:57, and one later.  But it looks to me
like your log analysis shows only successful attempts to send.

I would guess you can avoid greylisting by having Mailman send to
localhost rather than "mail".  (This depends on how you have
greylisting configured, if indeed that's the problem.)

Of course this could be completely off-base, but that's my best guess
based on the information you've provided.