This e-mail encryption software uses RSA public key encryption and Twofish block cipher; SecExMail features PGP style e-mail keys, but without the dependence on e-mail-software-specific plug-ins. The software runs unobtrusively as a relay agent in the system tray on your desktop and actively filters messages between your e-mail client and your mail server, encrypting and decrypting mail to and from known users in real-time. SecExMail now includes an HTML filter, which eliminates the chances of malicious attacks via HTML e-mail. SecExMail is certified to operate with all SMTP POP3 e-mail clients, including Microsoft Outlook, Netscape Mail, IncrediMail, Pegasus, The BAT, Eudora, and Calypso. SecExMail protects against cryptanalysis at the protocol level: e-mail subject lines are encrypted. All attachments to secure messages are autoencrypted, including their filenames and MIME-type information. SecExMail is built on the Open SSL secure socket layer library and is compatible with Crypto Anywhere. The latest version now supports automatic key exchange and will automatically configure popular e-mail clients via a wizard.