In order to comply with international anti-spam laws and our strict anti-spam policy, an unsubscribe link is required in every campaign.
Therefore, the presence of an unsubscribe link is validated every time a template is imported or saved.
To add an unsubscribe link, you only need to add the attribute "ibr-unsubscribe-link" to any "<a>" tag in your template.
Example:
<a href="#" ibr-unsubscribe-link>Unsubscribe from this mailing list</a>