Hello @Leah007 ,
Our system keeps track of what contacts unsubscribe from you, and prevents them from being sent emails, even if you try to re-add them to a list or re-upload them. The only way they can be re-added is if they explicitly sign back up through one of the resubscribe options:
If you're asking why we strongly recommend retaining those records for your own database outside of us, that's because an unsubscribe is considered legally-binding. This is regardless of what email service provider you use at the time. So if you move to a different service, or choose to send a marketing email directly from your address, we want you to have access to the unsubscribe info so you're being compliant with the contacts' permissions.
If you have additional questions on how unsubscribing works, make sure to check out our main article on the topic.
Community & Social Media Support
Did I answer your question? If so, please mark my post as an "Accepted Solution"
by clicking the Accept as Solution button in the bottom right hand corner of this post. Anyone can be a marketer! Visit our Blog & Resources page to brush up on the latest tips and tricks.