Update 3:05 PM: This issue has now been resolved. Any queued emails should be delivered to their destination shortly. We apologise for this inconvenience.
Initial report: Secure-ISS is investigating reports of mail delivery delays for some customers using our Email Security Gateway product. At this time we are unsure of the root cause, but our team are working to resolve this issue as soon as possible. We will update this page as more information becomes available.