This article describes how to bypass the sender domain check in FortiMail.
Scope
FortiMail.
Solution
Configure a new session profile and make sure the option 'Check sender domain' is disabled.
Configure a new IP policy for the sender IP that needs to bypass the 'Check sender domain', apply the new session profile above to the IP Policy, and configure all the relevant information, such as the 'Source' and etc.
Move the new IP policy with the new session profile to the top of all existing IP policies, and it should work now.
