If you purchased IMail Secure Server or ICS Premium releases 2006.1 or prior, your mail server includes Symantec's ScanEngine, one of the most comprehensive virus scanners available. As of release 2006.2 of the IMail product family, Premium Antivirus for IMail (Symantec's ScanEngine) is now available separately but still integrates seamlessly with IMail.
IMail Antivirus searches all incoming and outgoing mail for viruses, worms, trojan horses, and other destructive code. It does this by comparing all mail messages with a list of file extensions and known virus definitions.
It also uses heuristic technology to discover new viruses by searching for general characteristics of existing viruses. If it detects a virus, IMail Antivirus can attempt to repair the infected file, delete the message, or send a bounce message back to the sender. A log file entry is generated and an e-mail is sent to alert the administrator of the problem. In addition, the System Administrator can set a "Redirect Address" to send infected e-mail messages to. You can optionally send a message to the intended recipients informing them that the message could not be delivered.