Email Servers and Mac OS X - by Graham Orndorff, original publication date 2001.
Mac OS X Hints thread - scroll down for an updated rewrite of the preceding article.
Troubleshooting with Postfix Logs: by Kyle D. Dent, author of Postfix: The Definitive Guide - 01/22/2004 (at OnLamp, an O’Reilly site).
Send E-Mail Everywhere: Postfix on Mac OS X 10.3 Panther / 10.2 Jaguar. Step-by-step for CLI activation
PostFix Enabler bolts a GUI front end onto the vanilla Mac OS X postfix distro. Unfortunately it’s documented rather sketchily, and the SSL cert tool it sports has yet to perform reliably for me, prompting this research binge. I think I figured out how to set up certs at the command line when I set up sendmail but that was a couple of years ago, as I recall.
Even when I have been able to get the cert to take, Eudora chokes at login; the message I get looks to me as though Eudora is misreading EOL characters from the server.
So here’s a page on Eudora authentication errors.
I have a vague recollection of wrestling with UW-IMAP and the associated UW doohickeys to get Eudora to play nice; I thought that was all associated with the ‘secure-only’ reqs that is the current standard for email transfer.