SpamAssassin - Use this program to "Unspam" your mailbox(es).
Paubox - Paubox provides HIPAA compliant email encryption without the hassle of extra steps.
MailScanner - MailScanner is a open source email security system design for Linux-based email gateways.
Symantec Data Loss Prevention - Fully protect your data with the comprehensive detection technologies and unified policies of Symantec's industry leading Data Loss Prevention (DLP).
Rspamd - Rspamd is an advanced spam filtering system that allows evaluation of messages by a number of rules...
Microsoft BitLocker - BitLocker is a full disk encryption feature included with Windows Vista and later.