Clearswift's MIMEsweeper Email Appliance has several nice features, including a solid content filter and protection from spam, malware and undesirable content. We found this to be a pumped-up email data leakage prevention device with solid email protection. The content filter can pick out email that contains profanity and inappropriate content, sensitive and confidential data, as well as malware such as viruses, worms and Trojans.