avast! for Linux/Unix Servers offers real-time scanning of SMTP streams in the Linux/BSD environments. It is able to directly integrate with the most popular MTAs (SendMail, PostFix, QMail) or can work as a standalone SMTP gateway. All major distributions on the Intel platform are supported.

avast! for Linux/Unix Servers is an antivirus solution for the more and more popular Linux and BSD environments. Considering its robust design and mail scanning support, it is primarily intended for Linux (or BSD) based servers; it can be used on desktop computers as a desktop solution, but pricing assumes server usage.

Thanks to its flexible deamon architecture, avast! for Linux/Unix Servers can be used for both filesystem and network traffic scanning, such as real-time monitoring of mail (SMTP). (Source: Vendor Website)