After a report from a user that they were not able to get an email from someone I started poking into the exchange log files and quickly noticed multiple lines that read: 452 4.3.1 Insufficient system resources.
I checked memory, networking, CPU usage and finally hard drive space.  All seemed fine though my C drive only had about 1.95gb free.  I figured that didn’t sound like a lot but my mailbox databases are on a different drive that has 250gb free.  After a bit of research I found that Exchange 2007’s mail queue folder is by default on the C drive and will start throwing these sort of errors if there is less than 4gb of space.

So, I decided to move the queue folder (which currently was about 500mb) to a different drive.  I found the following command which easily moved the queue:

Move-TransportDatabase.ps1 -QueueDatabasePath: D:\Exchsrvr\TransportRoles\data\Queue -QueueDatabaseLoggingPath: D:\Exchsrvr\TransportRoles\data\Queue

Replace the D:\Exchsrvr…. with the path where you want the queue moved to.
The Move-TransportDatabase.ps1 script does the following:

  1. Free space is checked on the destination drive for the Queue Database and Queue Database Logs
  2. Create the destination path for the Queue Database and Queue Database Logs
  3. Assign Full Control permissions for Network Service, Local System, and Administrators for both paths
  4. Stop the Exchange Transport Service
  5. Backup the original EdgeTransport.exe.config file
  6. Move the Queue Database files, mail.que and trn.chk, to the destination folder
  7. Update the Queue Database path
  8. Move the file trn.log and any trn*.log files to the destination folder
  9. Update the path for Queue Database Logs
  10. Restart the Transport Service

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