This article is obsolete. Please read GPG Tools instead.
Add-on found to use GnuPG with Apple Mail under Snow Leopard!
A few months ago I decided to use MacOS Snow Leopard on my new Macbook Pro not Linux. Unfortunately Apple Mail didn't work together with GNU Privacy Guard. As a temporary work around I'd used a self-compiled commandline version of gnupg as mentioned on the privacy guard website. Encrypted mails I could decrypt to read them in a text editor.
Today I'd investigated this topic again and found this thread mentioning an inofficial add-on that works right out-of-the-box!
After update to OSX 10.6.3 this version will work again.
Again after updating Mac OS X to version 10.6.4 GPGMail needs to be installed in an updated version: All versions of the gpg-bundle you can find at http://github.com/lukele/GPGMail-SL/downloads.