SendGrid tracks email addresses for the following events:
Bounces
Unsubscribes
Spam Reports
Invalid Email Addresses
Email addresses that land on any of these lists are automatically dropped (i.e. not delivered to the destination ISP) in order to protect your sending reputation.
This forum provides answers to Frequently Asked Questions pertaining to the SendGrid managed email lists.
Note: The managed email lists are completely different from the email lists created for sending newsletters from our service.