Mailman: Relay access denied

[Matthew Thompson <wassoc@mattyt.net>]

Greetings,

I've searched Google and various mailing lists to no avail, so now I come to 
you all. :)

I just installed Mailman on my Potato server here at work and attempted to set 
up a test mailing list.  None of the welcome messages were sent out.  After 
digging around for a while, I found this in /var/log/mailman/smtp-failures:

server:/var/log/mailman# less smtp-failures
Mar 05 15:13:03 2001 TrySMTPDelivery: To mattyt@oz.net:
Mar 05 15:13:03 2001 TrySMTPDelivery:    Mailman.pythonlib.smtplib.SMTPRecipient
sRefused  / {'mattyt@oz.net': (554, '<mattyt@oz.net>: Recipient address rejected
: Relay access denied')}  (dequeued)
Mar 05 15:22:29 2001 TrySMTPDelivery: To wassoc@mattyt.net:
Mar 05 15:22:29 2001 TrySMTPDelivery:    Mailman.pythonlib.smtplib.SMTPRecipient
sRefused  / {'wassoc@mattyt.net': (554, '<wassoc@mattyt.net>: Recipient address
rejected: Relay access denied')}  (dequeued)
Mar 05 15:22:29 2001 TrySMTPDelivery: To mattyt@post.com:
Mar 05 15:22:29 2001 TrySMTPDelivery:    Mailman.pythonlib.smtplib.SMTPRecipient
sRefused  / {'mattyt@post.com': (554, '<mattyt@post.com>: Recipient address reje
cted: Relay access denied')}  (dequeued)
Mar 05 15:22:29 2001 TrySMTPDelivery: To jay@mattyt.net:
Mar 05 15:22:29 2001 TrySMTPDelivery:    Mailman.pythonlib.smtplib.SMTPRecipient
sRefused  / {'jay@mattyt.net': (554, '<jay@mattyt.net>: Recipient address reject
ed: Relay access denied')}  (dequeued)

I'm running Postfix as my MTA.  Any suggestions?

TIA :)

Cheers..................

Matt Thompson	wassoc@mattyt.net
Network Administrator
Williamson & Associates
http://www.wassoc.com