I am creating a HTML campaign, but I can‘t send it out. The error message says : “Your email does not contain an unsubscribe link“.

This is a warning because you have probably inserted a code without an unsubscribe link or with an incorrect unsubscribe link. All the templates must have a working unsubscribe link. Please Insert following HTML code line into the template:

<a href=”{$unsubscribe_link}”>{$unsubscribe_text}</a>