[Mailman-Users] Mailman and recipient spam filtering

[Stephen J. Turnbull]

Andrew Daviel writes:

 > My real question is, there are two types of "permanent" (500 series) 
 > rejection - recipient problems and message problems. I want mailman to 
 > auto-unsubscribe stale addresses after 5 (bounce_score_threshold) 
 > bounces, but I don't want active addresses to be unsubscribed because 5 
 > successive viruses or spams got through a relatively quiet list but were 
 > rejected by the recipient's filters.

Expanding on what Mark wrote:

It's not possible to reliably distinguish the two cases.  Besides the
large number of sites that give uninformative status codes to policy
(ie, "message problem") rejections, DMARC rejects get a "message
problem" status code, but they indicate that you just aren't going to
get through to that recipient.

If somebody who's had different experience wants to try the experiment
and show that it actually has potential for reducing undesired
unsubscriptions, I don't mean to discourage them.  But I won't do it
-- in my experience, such spates of spam getting through the list are
miniscule compared to the problems caused by rude and incompetent
receivers, so the effort is excessive compared to the return.

Steve