frozen messages on debian stable exim server

[Jared Marcum <marcum@ee.byu.edu>]

I have a mail server running debian stable that has a ton of messages 
frozen in the mail queue. The following four references seem to indicate 
I should perhaps turn on the sender_verify and receiver_verify options.

points 20 and 22 in /usr/share/doc/exim-tls/oview.txt.gz,
http://lists.debian.org/debian-user/2004/03/msg13134.html
http://www.exim.org/pipermail/exim-users/Week-of-Mon-20040419/070054.html
http://www.exim.org/pipermail/exim-users/Week-of-Mon-20040419/070061.html

However, since this is a production machine serving an entire University 
Department I'm hesitant to make the changes without being really sure 
it's the right thing to do. Can anyone verify that this is the right 
path? Are there any dangers of lost emails or other user-perceivable 
differences I should be aware of? Once these options have been added, 
are there any suggestions on how best to go about clearing out the 
emails already frozen? (exim -Mrm <message id> ??)

Thanks,

--
Jared Marcum
Brigham Young University
Electrical & Computer Engineering Department
Computer Systems Administrator
(801) 422-5728
marcum@ee.byu.edu