You can view any blocked senders and release here:
exchange online how to know if mailbox user was blocked
Hi all,
I suspect that 1 of my users has exceeded the limit - sent over 10000 messages a day and is blocked , how can I know for sure ? where can I find it ?
Exchange Online
-
Andy David - MVP 157.8K Reputation points MVP Volunteer Moderator
2023-02-10T12:27:12.6966667+00:00
2 additional answers
Sort by: Most helpful
-
Jack Chuong 436 Reputation points
2023-02-10T08:38:56.3833333+00:00 I have used Message trace to search all message from my suspect user in 7 days , many messages have status "Failed" but trace results is not clear , as you can see below
The subject is blank , so I think , my user password is revealed (she has changed it) and her mailbox was used to send many spam messages (exceed 10000 message a day), but I want to know for sure and remaining time of blocking.
-
Adrian Gallo 80 Reputation points
2023-02-10T07:04:42.63+00:00 You can check the message trace logs in the Exchange Admin Center to see if that user has exceeded the message send limit by following the steps below:
- Log in to the Exchange Admin Center (EAC) by going to https://outlook.com/admin and signing in with your admin credentials.
- In the EAC, go to the Mail flow > Message trace.
- You can select the date range for the trace logs you want to view on the message trace page and then click the search button.
- The message trace results will be displayed, and you can check for any blocked messages due to exceeding the message send limit.
- To filter the results, you can use the filter options on the right side of the screen, such as the result type, sender or recipient address, and message subject.
The documentation I suggest that may help with your question also is as follows:
- Message trace in Exchange Online - https://docs.microsoft.com/en-us/exchange/mail-flow-tools/message-trace/message-trace-in-exchange-online?view=exchserver-2019
- Understanding message trace in Exchange Online Protection - https://docs.microsoft.com/en-us/exchange/security-and-compliance/message-trace/understand-message-trace-in-exchange-online-protection?view=exchserver-2019
- Connection filtering in Exchange Online Protection - https://docs.microsoft.com/en-us/exchange/security-and-compliance/connection-filtering/connection-filtering-in-exchange-online-protection?view=exchserver-2019
Give it a go, and it will be great to hear your feedback.