[Mailman-Users] Delivery errors and spam grading

[Mark Sapiro]

On 3/18/19 5:39 AM, Stephen J. Turnbull wrote:
> 
> If you mean any other kind of delivery failure that is detected by the
> Mailman host, but is not returned to Mailman, then it is simply
> impossible for Mailman to even be aware of them, and you would have to
> check the MTA (mail server) logs.


However errors that occur during SMTP from Mailman to the outgoing MTA
are returned to Mailman. Mailman sees the SMTP status return and if it
is a 5xx status, scores that as a bounce and if it is a 4xx status
retries sending the message to the failed recipient(s) at configurable
intervals for a configurable time.

The retry interval is DELIVERY_RETRY_WAIT with a default of one hour,
but in MM 2.1.23, DELIVERY_RETRY_WAIT is ignored and the interval is 15
minutes.

The duration of retries is DELIVERY_RETRY_PERIOD with a default of 5
days, after which Mailman gives up without scoring a bounce.

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