[Mailman-Users] bouncing process does not return messages on user unknown

[Mark Sapiro]

On 06/03/2015 12:33 AM, Camelia Botez wrote:
> Thank you very much - indeed I checked and all the settings for bound process are OK.
> I checked also the maillog file for that particular mailing list and I saw different values for status:
> Stat : Service unavailable
> Stat : Deferred
> There are several external relay servers with verify=FAIL
> Or Recipient address rejected: Greylisted
> 
> 
> How mailman gets this status values ( as hard in bounce process ) , should it send back error messages to the owner / sender  .
> I'm sorry to disturb you with my questions but I'm very confused - how the mailing list gets back the errors and in what cases.


Mailman gets bounces in two ways.

1) If Mailman gets an SMTP recipient refused response to a recipient
during its SMTP transaction, this is logged in Mailman's 'smtp-failure'
log and a bounce recorded if the list is processing bounces.

2) For the kinds of things you are seeing in your MTA log, Mailman has
sent the message with envelope from LISTNAME-bounces at list.domain, or if
VERPed, from LISTNAME-bounces+recipient_user=users.domain at list.domain.

The MTA will send a DSN to that address and assuming it is deliverable,
Mailman will receive it and record a bounce if the list is processing
bounces.

In either case, a recorded bounce is logged in Mailman's bounce log and
scored. The DSN itself is discarded after processing unless it results
in a disable and bounce_notify_owner_on_disable is Yes in which case it
is attached to the notice to the admin.

Look at Mailman's 'bounce' log. If bounces are not being recorded,
ensure that the list's Bounce processing -> bounce_processing setting is
Yes and that the LISTNAME-bounces address is deliverable (you should see
the delivery of the DSN to Mailman in your MTA logs.

Note that for messages which are 'Deferred', they have to time out in
the MTA before Mailman receives an undeliverable notice. This typically
takes up to 5 days depending on the MTA configuration.

Greylisting is also a temporary failure in the MTA and normally the
message will be retried and accepted upon retry. This is not a bounce.

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