At approximately 6pm tonight, there was an issue with outbound external email delivery. Working with Microsoft we were able to resolve the issue by 7pm and continue to work on determining the root cause. Unfortunately, any email sent to an external recipient during that period will not be delivered and must be resent. You will know if any of your outbound email was affected as you would have received a notification email with “Subject: Undeliverable:” for the message(s) in question.