Microsoft Incident Report on Failure of Sending Emails

The following provides the summary of a Microsoft incident issued on 15 Oct 2020 (Thur).

Users Affected	Small group of Microsoft users, including CUHK staff & students
Start Time	8 Oct 2020 (Thur) 10:54PM
End Time	21 Oct 2020 (Thur) 6:00PM
Service Affected	Users might receive a Non-Delivery Report (NDR) when attempting to send email messages. The NDR error message readed “Message can’t be submitted because the sender’s submission quota was exceeded”.
Cause	A recent service update inadvertently caused an issue where sent emails are being miscounted, resulting in users being unable to send email messages.
Status	Microsoft fixed the issue.

Last update by Microsoft: 21 Oct 2020 (Thur) 6:00PM