There are two types of recipient-based policies: incoming and outgoing. The FortiMail unit applies incoming policies to the incoming mail messages and outgoing policies to the outgoing mail messages.

Whether the email is incoming or outgoing is decided by the domain name in the recipient’s email address. If the domain is a protected domain, the FortiMail unit considers the message to be incoming and applies the first matching incoming recipient-based policy. If the recipient domain is not a protected domain, the message is considered to be outgoing, and applies outgoing recipient-based policy.

To be more specific, the FortiMail unit actually matches the recipient domain’s IP address with the IP list of the protected SMTP servers where the protected domains reside. If there is an IP match, the domain is deemed protected and the email destined to this domain is considered to be incoming. If there is no IP match, the domain is deemed unprotected and the email destined to this domain is considered to be outgoing.

For more information on protected domains, see “Configuring protected domains”.