[Mimedefang] Conceptual stage at setting up email gateway

[webmaster+jnsolutions.co.uk at jnsolutions.co.uk]

I'm looking at setting up an email gateway for myself, due to the number of
emails that are either spam or viruses I seem to be getting.  I currently have
about 4 POP3 accounts plus I own two further domains.

The domains won't be a problem, as all I think I need to do is setup Mimedefang
with an email engine (e.g. sendmail?) on a server and that's then covered.

However, I'm not sure whether I can use a linux based email server to load the
pop3 accounts I use, and then check them for SPAM/Viruses.....

Is it possible?  And what do I need?

Cheers Nunners