Scenario
You notice that the signatures are not being applied to emails that are sent from an On-Premise mailbox.
After going through the Event Viewer on the Exchange Server, you see something similar to this:
Example screen of the Event Viewer.
An error message is displayed for every email sent through the routing agent.
Resolution
As displayed on the error message, "....your subscription has been marked as disabled."
Example screen showing the error message.
This issue can be due to several reasons. To investigate why this happened, please raise a Support ticket.