E-mail

The community docs for postfix and dovecot are pretty thorough. Postfix seemed not to work, and dovecot has issues. A restart fixed those issues, and hopefully signing my own certificates, as below, resolves the annoying server confirm thing that always used to pop up.

Here's how to sign your own certificates
http://www.debian-administration.org/articles/284

Here's something about converting mboxes to maildirs, but I don't know whether I want to do that just yet.
http://batleth.sapienti-sat.org/projects/mb2md/

Port Sniffing

nmap -sT -O localhost

Run it without root. It's cute.

http://www.redhat.com/docs/manuals/linux/RHL-9-Manual/security-guide/s1-server-ports.html