It is important to note that when a recipient opts to unsubscribe, your company cannot re-subscribe them. Manual resubscription on the entity records or through CSV imports is not possible. Only the recipient has the authority to decide to resubscribe.

These are the options to resubscribe the campaign emails.

1.  Through opt-in email

2. Opting-in through the Campaign Subscription Center

3. Clicking the Opt-In link in the footer of an email campaign message

It's considered best practice not to spam entities with opt-in email messages. You can monitor the number of opt-in messages previously sent to an entity by accessing the Subscription Message History subtab within the Marketing subtab. For more information, see