Deployment considerations
Applies to: Microsoft Antigen
For global protection throughout the enterprise, it is recommended that Antigen for Exchange be deployed on all Gateway and Mailbox servers. For optimal performance, all Gateway servers should have identical protection settings.
Before installing Antigen on a Mailbox server, you should conduct careful capacity planning and performance assessments to ensure that the server is operating with enough spare processing capacity to tolerate the extra load imposed by antivirus scanning.
The Antigen multiple engine architecture helps to maximize antivirus protection through diversity. Studies have shown that scanning with five engines decreases the window of vulnerability from the time that a new threat is encountered to the time that at least one engine vendor has released a protective signature. By default, messages are scanned only once by Antigen. However, it is a best practice to schedule background scanning on the Mailbox server to periodically rescan messages by using the latest available signatures.
Note
Because such a configuration is likely to negatively affect system performance, it is recommended that you do not use more then 5 scan engines for any given scan job.
To enable background scanning on engine update
Enable the Realtime Scan Job for the Storage Groups that you would like scanned by the Background Scanner.
In the Schedule Job pane, enable the Background Scan Job and schedule it to run at a selected date, time, and frequency.