Technical Tip: Configuring external email subject tagging in FortiMail using Session Action

Use the session profile Inbound_session to apply the external-subject tag to all inbound mail.

Go to Profile -> Session -> Session.

1. Select Inbound_session (or the relevant inbound session profile).
2. Expand Session Settings.
3. Configure Session Action and Message Selection as described below.

Session Action.

Select an existing action profile or create a new one.
The session action profile uses a content action profile.

• Create an action profile with only the Tag subject enabled.
• Assign this action profile under Session Action.

Refer to the following document for more details: Configuring content profiles and content action profiles.

Message Selection.

Choose where the action applies:

• All messages, or,
• Accepted messages only.

For subject tagging, Fortinet recommends applying the action to Accepted messages only.

Refer to the following document for more details: Configuring session profiles. 

Note: Ensure that the IP policy for outbound mail is placed above the IP policy for inbound mail, and that separate session profiles are used for inbound and outbound traffic.

Result:

The TAG EXTERNAL action has already been enabled for all incoming emails. A screenshot has been provided for reference.

This sample mail shows the '[EXTERNAL]' tag being applied.