You can configure the FortiMail unit to periodically request updates from the FDN or override servers for the FortiGuard Antivirus engine, antivirus definitions, and heuristic antispam rules (antispam definitions).

You can use push updates or manually initiate updates as alternatives or in conjunction with scheduled updates. If protection from the latest viral threats is a high priority, you could configure both scheduled updates and push updates, using scheduled updates as a failover method to increase the likelihood that the FortiMail unit always retrieves periodic updates if connectivity is interrupted during a push notification. While using only scheduled updates could potentially leave your network vulnerable to a new virus, it minimizes short disruptions to antivirus scans that can occur if the FortiMail unit applies push updates during peak volume times. For additional/alternative update methods, see “Configuring push updates” and “Manually requesting updates”.

For example, you might schedule updates every night at 2 AM or weekly on Sunday, when email traffic volume is light.

Before configuring scheduled updates, first verify that the FortiMail unit can connect to the FDN or override server. For details, see “Verifying connectivity with FortiGuard services”.