If you have a Top Marketer license, you can view a history of Newsletter events, including the date of each. The history includes when a contact has subscribed to a newsletter or viewed it, and any changes to their subscription status (including who requested the change).
To view a contact's Newsletter history:
Open the Contact
Record. How?
Click the Notifications tab.
All Newsletter notifications related to the displayed contact appear, including the dates of each.
Note: The Notifications tab is only visible if the contact has at least one Market Snapshot or Newsletter notification.
The following notifications are listed:
Newsletters that have been viewed.
When the contact subscribed to the newsletter.
Whether you or the contact stopped the subscription.