A-Lock - 3.8 

Type or receive Eudora, Netscape, Microsoft, cc:mail, ICQ, Hotmail, DejaNews,and much more. Mail the message as usual, then click the A-LOCK icon on your computer tray to automatically encrypt or decrypt. A-LOCK blocks snooping on shared and portable computers or while on the Internet is in use. A-LOCK is easy to use, with just one mouse click, and it displays the decrypted message in a private window while leaving the original message encrypted. A-LOCK includes a lockable password book with an option to specify a default encrypted password.

Crusader - 1.0 

This is a new and visually attractive encryption program that can send anonymous e-mails using Cyberpunk remailers. It automatically downloads remailer performance statistics and keys, it dynamically sorts and displays of all remailer data, and there is a spell checker.

Cycode - 4.2 

Very easy to use program that allows you to send encoded text files and e-mail messages. Includes many features such as base 64 encoding, passwords, and a cut and paste interface.

MAILGuardian - 1.11 

MAILguardian is a transparent e-mail encryption program which works with all SMTP/POP3-compliant e-mail utilities. It is easy to install and requires little update to insure that your e-mail is protected from prying eyes. MAILguardian is based on strong cryptography (DES, 3DES, and Blowfish). Hash functions (MD5) are used for digital signatures, and Diffie-Hellman is used for key management. MAILguardian supports multiple encryption methods and key lengths, so that your e-mail messages are compatible with international users who are subject to different privacy legislation.