I had a customer inform me over this Christmas period that they were not receiving any inbound e-mail from external sources, even though internal e-mail flow was fine as well as outgoing. I performed a quick inbound e-mail test at testexchangeconnectivity.com to discover that their Exchange 2007 installation on Windows Small Business Server 2008 was producing the following NDR error:
Delivery of the test message failed.
Additional Details: The server returned status code 452 – Insufficient system storage. The server response was: 4.3.1 Insufficient system resources
From looking at the error it can be concluded that this issue was definitely related to system storage. What had actually happened was that free disk space on the Windows system drive had dropped below a 4 Gigabyte threshold and as a result the Exchange Back Pressure feature had disabled inbound e-mail messages, as there was no longer sufficient disk space for the mail submission queue to function. This was further confirmed by reviewing event ID’s 15002 and 15006 in the Windows application event log. As I was struggling to free disk space on the system drive, I decided to move the Exchange Mail Submission Queue database to a separate disk where I had plenty of free resource. To perform this, I carried out the following procedure:
1. On a separate disk volume create a new folder structure, for example, D:\Microsoft Exchange\Queue.
2. Open the Exchange Management Shell and type the following command:
Move-TransportDatabase.ps1 -QueueDatabasePath: “D:\Microsoft Exchange\Queue” -QueueDatabaseLoggingPath: “D:\Microsoft Exchange\Queue”
3. The PowerShell script will now perform the move operation. Once this is complete, you should be informed the move was successful.
4. Navigate to the databases new folder location and confirm you can now see the queue database and it’s associated log files.
Your all done, you should now be able to receive incoming e-mail from external sources and hopefully avoid the issue happening again.