Mutt, POP3, and SMTP

["John R. Sheets" <dusk@ravendusk.org>]

I just recently switched over to Mutt, after using Communicator
for the longest time.  I'm having a little trouble getting Mutt
set up properly for POP3 (although I suspect my problem might be
deeper than Mutt).

In a nutshell, I'm running RH5.2 with very few tweaks.  I'm 
connecting to my ISP (pconline.com), which hosts my personal 
domain, ravendusk.org.  My /etc/hosts for my local machine
(raven.ravendusk.org) looks like this:

127.0.0.1       localhost       localhost.localdomain
192.168.25.25   raven           raven.ravendusk.org

In my mail, I set From: and Reply-To: to dusk@ravendusk.org, 
but somehow my mail gets rejected by certain recipients
because something along the chain tries to use
dusk@raven.ravendusk.org instead, which doesn't exist
in internet space (I'm using dynamic IP at pconline).
Here's a snippet from the MAILER-DAEMON message:

-----

Reporting-MTA: dns; raven.ravendusk.org
Arrival-Date: Tue, 8 Jun 1999 12:53:16 -0500

Final-Recipient: RFC822; bobr@dprc.net
Action: failed
Status: 5.0.0
Remote-MTA: DNS; mail1.best.com
Diagnostic-Code: SMTP; 518 <dusk@raven.ravendusk.org>... Sender domain must exist
Last-Attempt-Date: Tue, 8 Jun 1999 12:53:29 -0500

-----

What's going on?  Who's the errant party?  I'm a little
hazy on how it all fits together, so any background info
would be much appreciated.  I'd be happy to send more info.

Thanks,
John