[Mailman-Users] Postfix problem: Unknown local recipient. Mailman 2.1.4

[John Grunder]

I have just upgraded from Mailman 2.1.1 to 2.1.4 using an RPM for Mandrake
9, and am now getting the following warning log when I try to post to one
of the lists:

Mar 22 19:38:57 listserv postfix/smtpd[1664]: 761933AAD:
client=unknown[192.168.1.40]
Mar 22 19:38:57 listserv postfix/smtpd[1664]: 761933AAD: reject: RCPT from
unknown[192.168.1.40]: 450 <miis-la-alumni at listserv.miis.edu>: User
unknown in local recipient table; from=<jgrunder at miis.edu> proto=ESMTP
helo=<mail.miis.edu>
Mar 22 19:38:58 listserv postfix/smtpd[1664]: disconnect from
unknown[192.168.1.40]

Does anyone know what might be going on here?

I have checked the mm_cfg.py file and it contains the MTA = 'Postfix'
line, and have checked the Postfix main.cf file and it contains the
correct reference to /var/lib/mailman/data/aliases in its
local_recipient_maps line.  I even check the alias list using Webadmin and
the miis-la-alumni aliases show up there.  Postfix simply seems to be
rejecting miis-la-alumni as a valid local recipient. 

Any ideas on this?