A family of Microsoft spreadsheet software with tools for analyzing, charting, and communicating data.
Hello Mostafa!
Try disabling your Outlook AVG Add-in or your antivirus and see if it fixes the issue.
https://support.microsoft.com/en-us/help/285478....
Let me know the outcome.
With regards to your question whether it's possible to trace an email message, you can use the message trace feature to follow messages as they pass through your Exchange Online Protection service. With message tracing, you can determine whether a targeted email message was received, rejected, deferred, or delivered by the service. It also shows what events have occurred to the message before reaching its final status.
Here are some articles for a more detailed information.
Trace an Email Message:
https://docs.microsoft.com/en-us/exchange/monit...
Run a Message Trace and View the Results:
https://docs.microsoft.com/en-us/exchange/monit...
Hope this helps!
Jen :)