Hi @IT MAN ,
Is there any other information along with the error you mentioned?
Aside from the error, did the users encounter any mail flow issues when the error occur?
Which CU are you running? You can run the following command to view the build number:
Get-ExchangeServer | Format-List Name,Edition,AdminDisplayVersion
Besides, when the error appears, please follow the steps below to see if we can get more details for troubleshooting:
1.Run the following command in EMS to retrieve the HubTransport health set details about the server:
Get-ServerHealth <servername> | ?{$_.HealthSetName -eq "HubTransport"}
2.Review the command output and note the monitors that show as "Unhealthy".
3. Rerun the associated probe for the monitor that's in an unhealthy state. Refer to the table in the Explanation section to find the associated probe. To do this, run the following command:
Invoke-MonitoringProbe <health set name>\<probe name> -Server <server name> | Format-List
4.Review the result section in the output to see if there's any clues.
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