Anyone know anything about bugzilla and postfix?

I've got a system that I inherited, and then immediately had to move
it to a new company / new domain, etc.

Bugzilla has user accounts like "freda".

I have an entry in /etc/aliases for fredA:

freda:    freddy.krueger at

postfix is configured to relay to an exchange server (which handles
the e-mail for

postfix also has an recipient_canonical file, which looks like:

freda    freddy.krueger at

Things seem like they should be working - in fact, they kind of are...
if I go to bugzilla, and ask it to e-mail freda his password the
e-mail arrives in his inbox.

However, if I log in as fredA, and update a bug, bugzilla hangs.  The
browser that submitted the update never gets a page refresh, and the
bugzilla perl script hangs on the server.  One difference is that in
this case, it is trying to e--mail multiple addresses, instead of just

The only clue that I can find is the following from the mail.log file:

Jun  1 16:38:13 server postfix/smtpd[26483]: warning: non-SMTP command
from[]: X-Bugzilla-Reason: CC

How can I further debug this?