I have users who are experiencing the following error:

The following recipient(s) could not be reached:

' on 9/13/2007 10:15 AM

554 5.7.1 c-76-16-40-85.hsd1.il.comcast.net[76.16.40.85]:
Client host rejected: Check your mail first

I believe the error may be a PTR issue, but another issue I have is as
follows:
Each time an undeliverbale message like the one above is recieved, the
intended recipient's name is removed from the drop-down autocomplete
(nickname) list used when composing a new message. So for the example above,
would no longer be in the nickname list. The only way to
get them back in is to shut down Outlook (2003 R2), restart it and compose a
new message to that recipient. I have tested this on my own Outlook by
sending to an old address that doesn't exist anymore, and the name stayed in
the list. Anybody know why this is happening?


Thanks,

Matt