Proofpoint Essentials e-mail filter

Use our new security improvement product: Proofpoint Essentials filter for e-mail. Inbound and optionally Outbound. E-mail to and from your business domain will be thoroughly scrubbed for threats and spam. Severe risk items are immediately & safely deleted; suspicious content is quarantined and your staff may then quickly and safely delete, deliver, or white-list those items.

Here is a shortened list of features, actual mail server results are shown below.
99.999% Service Availability, 99% Spam Effectiveness, 100% Protection from known viruses, < 1 minute email delivery

Signature-based Anti Virus
Spam Filtering
Reporting
Content Filtering
Outbound Filtering
Zero Hour Threat Detection
URL Defense
Attachment Defense
Data Loss Prevention
Emergency Inbox
E-mail Spooling
Instant Replay
Multi-level logins
Domain Management
E-mail Logs