[Mailman-Users] listname-bounces@

[Stephen J. Turnbull]

Michael Welch writes:

 > Right, that must be because this list's Sender: header does not
 > look like a real email address. I wonder why ours are different.

It's one of the "VERP" settings.  While "true" VERP is done by the
MTA, not by agents like Mailman, the basic idea is the same: to
"personalize" various fields in the message so that the original that
elicited a reply (including a bounce) can be identified.

IIRC there are two.  One which enables VERP for various administrative
messages which allows occasional checking for bounces, the other
enables it for all messages.  I believe this is possible on a per-list
basis.  You want the latter.

The downside is performance, which is why VERP off is the default.
Each message has to be composed individually, which increases the
processor load a bit.  This is probably negligible.  More important,
each message has to be sent individually, which can dramatically slow
down processing if you have any large groups of members served by a
single receiving MTA.  (It is possible to specify multiple recipients
for a single message; the receiving MTA will fetch it from the network
once, then distribute copies.  Sort of like you fax a handout to the
meeting organizer, and he makes Xeroxes for all the attendees.  Much
more efficient than faxing one to each attendee!)

I'm still on Mailman 2.1.5 which doesn't seem to have this feature, or
maybe it's only available through the command line interface.  If it
sounds like what you need, say so and I'm sure somebody will tell you
where the setting can be made.  Note that this configuration may be
disabled or objectionable to your ISP because of the possible impact
on performance.