FortiMail provides advanced, multi-layer protection against the full spectrum of email-borne threats
Article Id 195236
This article explains how to enable the Sender Alignment feature in FortiMail. Sender alignment is a feature that checks the matching between the header from and the envelope from.

To enable the Sender Alignment feature, go to Profile -> Antispam -> Select the Antispam profile which applied to recipient policy or IP Policy.

If an email is sent to FortiMail with different envelope from and header from, the following log will appear in FortiMail “SPF=SENDER_ALIGNMENT: ( From value: dns@lab.local) does not align with authorization domain