[Mailman-Users] bounces

Mark Sapiro mark at msapiro.net
Wed May 5 05:16:34 CEST 2010

Grant Taylor wrote:

>kalin m wrote:
>> so if it's not 5xx it's not a bad email?  i see dsn=4.0.0. that's not 
>> enough?
>In SMTP 4.y.z DSNs are "temporary" errors.  They could be caused by a 
>spam filter over loaded, or the system shutting down, or...
>> i'm assuming it's retried by the mta. the settings in mailman clearly 
>> state that it should be discarded right away...
>The 4.y.z should be seen as an invitation for the SMTP server to try 
>sending the message again at a later time.
>The MTA will eventually time out the message and generate a permanent error.

Or, if the MTA returns the 4xx status directly to Mailman during SMTP,
Mailman will retry the send every DELIVERY_RETRY_WAIT (default 1 hour)
for DELIVERY_RETRY_PERIOD (default 5 days), but in this case, mailman
will eventually give up but not record a bounce.

If this is the case and you want Mailman to record a bounce, you have
to arrange for your MTA to return a 5xx status for an invalid
recipient domain.

So the first question is where is the message. Is it queued in the MTA,
or is it in Mailman's retry queue. If it's queued in the MTA, as Grant
says, the MTA will eventually time out on this message and return a
hard bounce to Mailman. If it is queued in Mailman, mailman will
eventually give up and no bounce will be recorded.

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

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