Elm supports PGP "out of the box." Enabling GPG takes only a little bit of work. One very short path to support is to use a shell program that "wraps" GPG with commands that look and work like the old PGP 2.6.2 commands. This is a solution for full compatibility with a lot of old PGP supporting applications.
This compatibility package is called pgpgpg. Here's some info :
Package: pgpgpg
Homepage: http://www.nessie.de/mroth/pgpgpg
Download: ftp://ftp.gnupg.org/pub/gcrypt/pgpgpg-0.13.1.tar.gz
Once you have this installed, you can use the older PGP commands (which is what elm will do!) to enable PGP support.
As of this writing, the most current version of mutt is 1.2.5i. Mutt has optional support for PGP at compilation. As with elm, you can get mutt working by using pgpgpg.
Even without direct support, you can use the "F" (filter) command to send your message attachment through GPG for signature and/or encryption. You can use the pipe (|) command on the receiving side to send your message through GPG for decryption and signature verification.
Here again someone has done all the work for us. There is a program called gpg4pine. Here's some info:
Package: gpg4pine
Homepage: None (alas!)
Download: http://azzie. robotics .net/
Complete directions are included with the software. (Try this too!)
The newest versions of Kmail support GP6 directly, but older versions can support it through a PGP compatibility wrapper. Once you have installed gpgpgp, you open File/Settings, and select the PGP tab, as shown in Figure 10-1 .
These mail clients are so basic and primitive that not even I use them. As it happens, it is simple, if inconvenient, to use GPG with these programs. You must sign or encrypt your mail as a text file outside the program and then redirect the file in to send it. To read such mail, you must save the message to a file (using the save or copy commands), and then run GPG on the file directly.
Netscape does not support GPG decently. You must "presign" and/or "pre-encrypt" your messages; you must save your messages to files to check signatures and decrypt. Sad, isn't it?