FortiMail units can log many different email activities and traffic including:

You can select which severity level an activity or event must meet in order to be recorded in the logs. For more information, see “Log message severity levels”.

A FortiMail unit can save log messages to its hard disk or a remote location, such as a Syslog server or a Fortinet FortiAnalyzer unit. For more information, see “Configuring logging”. It can also use log messages as the basis for reports. For more information, see “Configuring report profiles and generating reports”.