Old: $new_settings['emailtemplates'][$tpl]  = addslashes(mga_stripslashes_deep($settings['emailtemplates'][$tpl]));

New:

$allowedtags = array('href' => array(),
            'title' => array()),
            'br' => array(),
            'em' => array(),
            'strong' => array());

$new_settings['emailtemplates'][$tpl]  = wp_kses($settings['emailtemplates'][$tpl],$allowedtags));