What happens when a contact unsubscribe?

What happens when a contact unsubscribes?

When a contact unsubscribes, they are automatically unsubscribed from all topics in the organization. They will no longer receive any email campaigns from the organization. 
  1. If the contacts were moved to Unsubscribed by you, you can move them back to All Contacts if required.
  2. If contacts are present in the Unsubscribed filter, you cannot delete them; you can only export them. The reason we have not provided the option to delete them is to avoid adding the same "unsubscribed contacts" into your Zoho Campaigns account in future.
  3. The only way unsubscribed contacts can resubscribe is through a Zoho Campaigns signup form.