Back pressure issue Exchange 2019

Copper Contributor

Hi all,


We are migrating from 2013 to 2019CU13.  During migration of mailboxes, the partition exchange is installed on ran out of hdd space.  Moving too much between backups so the logs filled up.  Am getting the Back Pressure error 15006.



I saw this can be resolved by moving the queue database to another partition.  I successfully did this by editing EdgeTransport.exe.config and restarted the Transport service. I am still getting the error though.


While not recommended, I added the key to disable resource monitoring (we need mail flow while we figure this out), but that hasn't worked either!


We can send mail externally, internal mail works but not incoming.  The system we have in front is reporting in its queue:


452 4.3.1 Insufficient system resources (UsedDiskSpace[C:\Program Files\Microsoft\Exchange Server\V15\TransportRoles\data]) (in reply to end of DATA command)


Is there something else I need to do to get this working again?


thank you




EDIT: Resolved! I also moved the IPFilter and TemporaryStorage paths and back pressure has eased.

1 Reply
Glad you got it solved. You could have also fiddled with the free percentage threshold, but this is better :)