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

Whether the email is inbound or outbound 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 inbound and applies the first matching inbound recipient-based policy. If the recipient domain is not a protected domain, the message is considered to be outbound, and applies outbound 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 inbound. If there is no IP match, the domain is deemed unprotected and the email destined to this domain is considered to be outbound.

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