OutlookCrypt is an free encryption tool designed for Microsoft Outlook 2003 which enable users to encrypt and decrypt e-mail messages. It works on a strong 128-bit symmetric encryption algorithm (CAST5), which allows both sender and recipient to encrypt/decrypt the message through predefined passphrase keys. The encryption/decryption processes are fully integrated with Outlook 2003 so that the messages can be encrypt/decrypt just by clicking a button.