Testing for and stopping mail relaying

[Erich S.]

Happy Holidays! :)

In spare time during the holidays, I've wanted to find more information on
securing sendmail 8.9.3 against relaying was well as blocking spammers.

Are there any relatively simple HOW-TO sites that deal with this? The
information at sendmail.org that I saw seems to be more for experienced
sendmail admins.

Are there other, easier to admin mailservers that can replace sendmail?
What are the downsides to using them? I've heard some good things about
qmail, but not sure if there are disadvantages to using it vs. sendmail.
I'm using sendmail only since it's what is installed now, and what appears
to be installed on most other boxes I've come in contact with.

Thanks in advance for any pointers in the right direction!

Aloha,
	Erich