Prospect.io allows you to add an opt-out link at the bottom of your emails to let the prospects unsubscribe from your mailing list. By default, an unsubscribe link is not included in the emails, but the account admins can turn it on.
To enable this option, navigate to the Settings > Emails > Opt-out Link.
Decide whether you want to include the opt-out link to all emails or let your users enable or disable the feature for them separately. Here you can also change the link text.
If you choose the latter option, the users will be able to turn the opt-out link on or off from their Sending Address page.
The unsubscribed prospects are automatically added to your Exclusion list, you cannot manually resubscribe them.