When Mail Security is installed on a Microsoft Exchange Mailbox server and background scanning is enabled, Microsoft Exchange creates a background thread for each message database in the Exchange store. These threads run at a lower priority to minimize the impact on other Exchange server actions. As each thread reads through the messages in the database, it detects the messages that have not been scanned by the latest definitions and scans them. This is useful if you have updated your definitions and need to re-scan the entire store with new definitions.
You can also scan the email messages that have attachments and specify which messages to scan based on the message date.
Mail Security enables the Exchange VSAPI background scanning feature. Based on the load and Microsoft Exchange's algorithms, Microsoft might interrupt the background scanning process.
To configure background scanning
In the console on the primary navigation bar, click Scans.
In the sidebar under Views, click Auto-Protect.
In the content area, under Background Scanning Options, check Enable background scanning.
You can select this option only when Enable Auto-Protect option is checked.
Do one of the following:
In the schedule matrix, click the boxes for the days and hours during which you want background scanning to occur.
Under the schedule matrix, click the drop-down list and select the day that you want background scanning to occur, the time that you want scanning to start, the time that you want scanning to finish, and then click Select.
Click Select All to select all day and time ranges.
The boxes in the schedule matrix are blackened to indicate the time frames that background scanning will occur.
Click Clear All to clear all of the options that you selected.
You must indicate a time range for background scanning to run.
Check Scan messages with attachments only to scan email messages and their attachments that are in the mailbox store.
Mail Security only scans the messages that have attachments when you select this option.
Under Choose messages to scan, select one of the following options:
On the toolbar, click Deploy changes to apply your changes.