If your contact wishes to unsubscribe from receiving email and/or sms marketing notification, follow the steps below:
Once you're logged in to your workspace account, click Contacts on top of the page.
Type in the name or the email of the contact in the search field to quickly search for it.
Click the contact's name in the search result. That should take you to the contact's page.
Select whether to unsubscribe from email marketing or sms marketing, or both. No need to save the changes as it will just auto-save.
See it in action: