[Mailman-Users] Is this a mailman or postfix error?

[roy vinner]

Greetings!

I have a problem that any address which is supposed to be resolved with
the path-to-mailman/data/aliases produces a "message undeliverable" error.

I've also discovered that if I run an alias expansion from the command line

aliases:
..............................................
# STANZA START: try
# CREATED: Mon Jul 25 17:19:03 2005
try:             "|/usr/local/mailman/mail/mailman post try"
try-admin:       "|/usr/local/mailman/mail/mailman admin try"
try-bounces:     "|/usr/local/mailman/mail/mailman bounces try"
try-confirm:     "|/usr/local/mailman/mail/mailman confirm try"
try-join:        "|/usr/local/mailman/mail/mailman join try"
try-leave:       "|/usr/local/mailman/mail/mailman leave try"
try-owner:       "|/usr/local/mailman/mail/mailman owner try"
try-request:     "|/usr/local/mailman/mail/mailman request try"
try-subscribe:   "|/usr/local/mailman/mail/mailman subscribe try"
try-unsubscribe: "|/usr/local/mailman/mail/mailman unsubscribe try"
# STANZA END: try
..........

[mailman at nrg mailman-2.1.6]$ /usr/local/mailman/mail/mailman request try
Failure to find group name mailman.  Try adding this group
to your system, or re-run configure, providing an
existing group name with the command line option --with-mail-gid.

I have re-run mailman's configure as requested by the above message and
group mailman does exist on my machine. I am clueless as to what is awry
here with postfix aliases? Is this a postfix or mailman problem?

Let me know if you need any more information for logs or config files.

Thank you for your suggestions.

Thankfully,
Roy