List-Unsubscribe Header Not Showing Up in Emails

Issue

Issue Description
You have sent an email and do not see the List-Unsubscribe headers.

 


Solution

Issue Resolution
Marketo automatically adds the appropriate List-Unsubscribe headers to emails, EXCEPT in three scenarios:

 

1) The email is marked as operational

2) You are sending a test email via the "Send Sample" action

3) The email is an alert email

 

In these cases, the List-Unsubscribe header will not be added to the email.