[Mailman-Users] Messages delivered out of order and delayed

[Mark Sapiro]

On 9/13/19 6:59 AM, Veronica Morris wrote:
> I run an active discussion group.  Messages come and go from people all
> hours of the day.
> 
> For the past few months, we've noticed that messages are arriving out of
> order, and sometimes are delayed by hours or even a day!
> 
> The kicker is that the delivery issues are not the same for everyone.  Some
> people will get a particular message immediately, while others will get
> that message in an hour, and others in a day.
> 
> Most of our users use gmail.
> 
> What can we do to fix this?  As ours is a discussion group, timing is
> pretty important so that the flow of the conversation isn't interrupted by
> people not having read previous messages.


First, it appears that message delivery from Mailman is slow. There are
multiple possible reasons for this. It can be that SMTP delivery from
Mailman to the outgoing MTA is slow - see the FAQ at
<https://wiki.list.org/x/17892002>. If this is the case, the FAQ has
some suggestions for fixing this.

It can also be the case that delivery from the outgoing MTA to the
various recipient MTAs is being throttled by the recipient MTAs.
Examination of the outgoing MTA's logs should reveal this.

Also, if people reply-all to posts rather than replying just to the
list, the direct recipients will probably get the reply before the other
list members.

In short, you need access to Mailman's logs and the outgoing MTA's logs
in order to diagnose this further.

-- 
Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan