Inside firewall mail server questions

I have an old pentium with Red Hat Linux 7.3 installed. No GUI. Has Web=
min. =20
Works fine. My goal is to set this up as a mail server here at home. My=
ISP=20
filters most of the spam but I want to filter what gets through them. Th=
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concept is this:

- The mail server uses fetchmail (or a similar tool/function) to ahem.. f=
etch=20
the mail.
- A program like spamanator filters out the garbage.
- The mail is put in user mail boxes.
- The client computers retrieve their mail via the POP server.
- The client computers send mail out via the SMTP server (qmail, I think)=
=2E

Never having done this sort of setup before, I have some questions:
1. This server is inside the firewall. I don't want it as an email serve=
r on=20
the net. My ISP can do that. Fetchmail can handle this, correct?
2. Any recommendations on spam programs like spamanator? Something bette=
r?
3. I have not researched yet what apps do the POP function. Is it the sa=
me=20
app as the SMTP function? What app is a good one for this?
4. Any other advice for a first time mail server admin?

This should be fun!

Alan