Keep certain tags in your campaigns

By default, Mailster will remove all unused tags in the final version of your campaign. To prevent that you can whitelist certain tags with some custom code.

add_filter( 'mailster_keep_tags', function( $tags ){
    $tags[] = 'my-special-tag';
    $tags[] = 'my-other-tag';
    return $tags;
});

This will keep {my-special-tag} and {my-other-tag} in your campaign as good variations like {my-special-tag:123} or {my-other-tag:456|my_fallback}.