This article is meant for the MassMailer new edition.
You can view the suppressed emails in MassMailer such as Unsubscribes, Hard Bounces, Spam Reports by going to the 'MassMailer Suppression List' tab as shown in the following picture.
You can also go to the respective object that has the email address and, view the related list called 'MassMailer Suppression List' as shown in the following picture.
