MailRecon is email content control tool which helps to fight with leaking of confidential information in email messages. It works very similar to FBIs Carnivore program. It passively listens to network, captures email traffic, checks each message against set of rules, and saves suspicious messages. Compatible with all SMTP/POP3 software for any OS. Doesn't require any integration into current mailing system and can capture even messages which were sent bypassing your mailserver. Captured messages are stored in Maildir, so it's possible to read it with any mail reader or with browser via webmail.