[Mailman-Users] Large lists and Postfix

Dave Sill ds-list-mailman at sws5.ctd.ornl.gov
Tue Mar 16 14:25:52 CET 1999

bruce at hams.com wrote:

>However, the main overhead of mailing lists is their overhead on
>_your_time_ to manage them, not the computer.  Mailman is very good
>about reducing _that_ overhead, much better than ezmlm.

I'm a long-time majordomo user who's evaluating alternatives including 
ezmlm, mailman, and listar. I'd appreciate an explanation of how
mailman is better at reducing the list manager's overhead than ezmlm.

>Ezmlm's main advantage is that it uses the qmail "percent hack" to get

Actually, it's called "VERP" (Variable Envelope Return Path), not
"percent hack". The "percenthack" qmail configuration variable turns
on user%host at relay style relaying. But your explanation is, otherwise,

>If my address bounces, the bounce mail goes to that address, a qmail default
>rule catches it, and ezmlm decodes bruce%hams.com and realizes that I've
>had a bounce. It doesn't have to look at the bounce message at all, just
>the address it goes to.

Right, and the neat thing about this from the user's point of view is
that ezmlm keeps track of which messages each recipient bounces so if
the problem is temporary, it tells them and they can retrieve the
messages from the archive.

>When I get sick of watching undecoded bounces go by, I'll add that "percent
>hack" feature to Mailman.

You really need VERP support in the MTA, otherwise you'll have to
inject a copy of each message to each recipient. Right now, qmail is
the only MTA I've aware of that does VERP. Venema wants to add it as
an option to Postfix, though.


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