Contained within the header of an email are details that you may need to access for legal purposes, such as a Storage Reference, Message Key, and other unique IDs. If you need to check the header of an email, you can do so as follows:
Log in to your archive, and select the email containing the headers you want to check.
Scroll to the bottom of the email, and select Security Verified, a term that means the email has not been tampered with. After you select it, unique details of the email are displayed.
In addition to the Storage Reference, Unique Message Signature, Message Key and Original Message ID, it also displays the date that the email was stored in ArcTitan.