Ok, I finally managed to set up my GPG Mail System. Thanks to the latest version of GPGMail and gpg (1.4.10) (via macports sudo port install gnupg) it’s running fine and smooth again with Snow Leopard and Mail.app. Perfect!

See MacGPG and GPGMail for more…

Find my GPG-Key here

UPDATE: btw. to get GPGP work with gmail, check out FireGPG, a nice plugin for Firefox, which works perfect for me on Mac OS X. Unfortunately I haven’t found any Safari solution yet…