Hi, I am setting up Mailman with sendmail and apache2, and when I try
to subscribe an address to the list with "send notifications to
subscriber" turned on, I never receive the email.

logs/smtp says:

Feb 18 01:08:17 2007 (77993) <mailman. 0.1171789696.78619.mailman@sub.domain.net> smtp to mailman for 1
recips, completed in 0.018 seconds

logs/smtp-failure says:

Feb 18 01:08:17 2007 (77993) SMTP session failure: 553, 5.3.0
<mailman-bounces@sub.domain.net>... User unknown, msgid: <mailman. 0.1171789696.78619.mailman@sub.domain.net>

I'm trying to figure out how to push the email through and I'm
stuck. What could the problem be?

(...)

In the process of writing this email, I figured out the problem. I
figured I'd send this anyway for future google searches.

Many sendmail utilities automatically put a catchall in virtusertable: @sub.domain.net error:nouser User unknown

So even though you wouldn't normally have to put entries in
virtusertable, you do in this case, BEFORE the catchall, since
virtusertable is interpreted before the aliases file. So once I put:

mailman@sub.domain.net mailman mailman-admin@sub.domain.net mailman-admin mailman-bounces@sub.domain.net mailman-bounces mailman-confirm@sub.domain.net mailman-confirm mailman-join@sub.domain.net mailman-join mailman-leave@sub.domain.net mailman-leave mailman-owner@sub.domain.net mailman-owner mailman-request@sub.domain.net mailman-request mailman-subscribe@sub.domain.net mailman-subscribe mailman-unsubscribe@sub.domain.net mailman-unsubscribe

in the virtusertable and reran /etc/mail/make, things started working.

The mailman documentation doesn't mention this.