[Error]: Signature is not applied due to disabled subscription

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:

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:

This issue can be due to a number of reasons; to investigate why this happened, you can either:

• Raise a Support ticket, OR
• Email your Exclaimer Account representative.