I'm looking for encryption solutions for not just files / folders, but also for email. Years ago I used PGP for email, are there any recommended mail.app plugins or anything that use encryption?
I don't have a mac yet, so I can't really answer this question, but when I do get one, I'll look into it, so if you find one, let me know.
Just one thing though: are you sure you want encryption, and not a checksum program that verifies the integrity of the message? If your e-mails are so top secret that you need something like PGP, maybe that's a better solution.