You may make changes to the attributes of all secure emails that you have sent, as well as monitor their access history, from the Sent Email folder. Simply select your Sent email folder and you will be provided with a set of action buttons as shown in the screen below:
These tools provide the ability to see who has accessed each secure email, and when. You also have the ability to revoke access to previously transmitted secure emails (known as “disabling”), or to remove the contents permanently (known as “shredding”). Previously disabled contents can be re-enabled so long as they were not shredded.