This issue should now be resolved, Mailgun have stated that email dispatching should now be fully functional, thanks for your patience and understanding.
You may notice a delay receiving email notifications for your pickup, delivery and shipping orders. This is due to an outage with our mail service provider; Mailgun. We will keep this page updated and do what we can to ensure a speedy recovery. You can view realtime updates from Mailgun themselves here: https://status.mailgun.com/.