[Mailman-Users] Analysis of reasons for bounce responses

[Ed Wilts]

On Sat, Aug 02, 2003 at 07:32:09AM -0700, JC Dill wrote:
> At 09:30 PM 7/31/2003, Christine De La Rosa wrote:
> >Hi Richard,
> >
> >Here is what I know so far, mail for most list members seem to be going
> >through for the most part.  About two weeks ago MM mass unscribed about
> >300 folx. Now we seem to have stablized the members but the owners of
> >the lists are getting routinely bounced.  Yahoo email address do not
> >have a problem, aol is a major headache as is hotmail.
> 
> This is a big clue that the MTA is improperly configured and is trying to 
> deliver to the AOL and Hotmail servers messages for more recipients than 
> those systems allow - triggering anti-spam filtering on the recipient MTA 
> at AOL and Hotmail.  The messages are then bounced.  My guess is that they 
> changed the MTA at around the same time they upgraded Mailman, and you are 
> barking up the wrong tree to try to find the source of the problem.

A quick test would be to drop the maximum number of recipients in
Mailman.  In mm_cfg.py, set SMTP_MAX_RCPTS to 20.  Details are in
Defaults.py.  This will chunk your messages to a maximum of 20
recipients at a time.  Some people have done performance tests to
suggest that dropping this to about 5 will give you better throughput.

-- 
Ed Wilts, Mounds View, MN, USA
mailto:ewilts at ewilts.org