Delete or unsubscribe a contact
We don't recommend deleting contacts but changing their status to unsubscribed. This way, you can't accidentally re-subscribe them later. Unsubscribed contacts are maintained in your list but no longer count towards the subscriber count of your plan.
For each list where the email address is Subscribed, do the following:
Click on the list. At the upper right part of the page there is a search icon, click the magnifying glass to search for the email address or find it in the contact list and click on the address.
Now you have two options: You can delete or you can edit the Contact. Deleting the contact will remove them from this list and the reporting data from the contact. If you click Edit, then you are able to change the subscription status to unsubscribed and then Save. Unsubscribed means the contact can no longer receive an email from this list.