MTA help

[Eric Walstad <debian@ericwalstad.com>]

Greetings kind debianites,

I'm in the process of learning MTA admin.  My head is about to explode.

I'm wanting to setup a Debian box that'll suck down pop email from an 
ISP for a few local users and then serve those email up via pop3 or 
imap on the LAN.  Following some advice I received on this list, I 
installed fetchmail, courier-imap, courier-pop and exim4.  I then found 
that exim4 and courier like different mailbox formats.  I couldn't find 
a way to make exim4 work with courier's maildir format, so I figured 
I'd replace exim4 with courier-mta.  Now fetchmail and courier-mta are 
fighting (courieresmtp throws an ERROR 513, syntax error, when 
fetchmail tries to forward an email) over addresses like 
"ewalstad@localhost".

So, I'm stuck.  I haven't had any luck in figuring out how to fix 
courier and I don't know how to fix exim4.

Any sage bits of advice are appreciated.

Eric.

PS, I hope you mail admins get paid a LOT of money for what you do.  I'm 
finding email setup and admin is very complex.