CryptoLab is a freeware cryptography application for Microsoft Windows, and incorporates text-based Encryption / decryption through the use of plug-in cipher modules. Advanced features include SMTP email support, a Key Manager and pseudo-random key generation.
See at http://www.ejc-crypto.co.uk/
EJC Cryptography is an online information security company which specialises in both classical Encryption methods and modern day algorithms, making them available for use by computer users and cryptography enthusiasts around the world for free.