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Configuring FortiMail Relay for Separated Domain Scenario

Hello Fortinet Community,

I am reaching out for assistance regarding the configuration of FortiMail in a scenario where our internal domain is different from our external domain. Our internal domain is domain.lan, while the external domain is

We have a mail server named mail.domain.lan within our internal network, serving internal users whose email addresses follow the format user@domain.lan. However, we require incoming emails from external sources to be directed to

I'm seeking advice on whether it's possible to configure FortiMail to relay external emails to our internal network while converting the domain suffix from to domain.lan (see picture).

Any guidance on this matter would be greatly appreciated.

Thank you for your assistance.fortimail.png

Best regards,

IGHIL Khaled



Hi Khaled

I don't think such suffix conversion exists on FML.

I remember I've already seen one company had at the same time two mail domains but the second was a kind of alias of the first. So I think the solution would be to do something similar (add as alias) then forward the incoming mail as is (to: to your internal server.


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