[Mailman-Users] How can I tell WHY sendmail is refusing posts from/via mailman?

[Scott Brown]

PLEASE help me out - I'm running mailman 2.0 on a RH 5.2 system, using
sendmail 8.8.5... and this is my last problem to figure out....

All the pieces of mailman are in place, the cron entries are running, all
the uid's and gid's match, and the webside of things works just peachy.

Mailman will receive posts (the /home/mailman/logs/SMTP  file shows them
being received).  The qfiles directory holds them for a bit, and then
qrunner starts up and attempts to send them.

But it doenst send successfully.

I dont believe this is anything to do with mailman itself - it is trying to
inject the mail message through sendmail - but sendmail is barfing on it....

my /var/log/maillog file show:

Dec 13 21:33:01 apollo sendmail[13821]: VAA13821: <scott-brown at home.com>...
relay attempt failed
Dec 13 21:33:01 apollo sendmail[13821]: Ruleset check_rcpt
(<scott-brown at home.com>) rejection: 550 <scott-brown at home.com>... relay
attempt failed
Dec 13 21:33:01 apollo sendmail[13821]: VAA13821:
from=<test-admin at host-ops.com>, size=1670, class=0, pri=0, nrcpts=0,
proto=ESMTP, relay=localhost [127.0.0.1]

Can someone give me an idea as to what I need to do to get sendmail to
accept these messages?