Refer to the exhibit showing the history logs from a FortiMail device.

Impersonation analysis is a feature that detects emails that attempt to impersonate a trusted sender, such as a company executive or a well-known brand, by using spoofed or look-alike email addresses. This feature can help prevent phishing and business email compromise (BEC) attacks. Impersonation analysis can be enabled in an antispam profile and applied to a firewall policy. References:https://docs.fortinet.com/document/fortimail/6.4.0/administration-guide/103663/impersonation-analysis

https://docs.fortinet.com/document/fortimail/7.2.0/cookbook/221814/protecting-against-email-impersonation-in-fortimail