I have a single multi-role Exchange 2013 server and it would appear that it's not properly maintaining the temp files for the transport service.  I still have all those folder locations at their default and the problem folder is c:\Program Files\Microsoft\Exchange Server\V15\TransportRoles\data\Temp

I never had a problem with this in Exchange 2007 but I am used to running a PowerShell script nightly to clean up the IIS log files.  Do I need to do something similar for this temp folder?  Is there a setting I can adjust so that Exchange will limit the size of this folder itself?  If I stop the transport service and delete the files here will I lose anything?

Any suggestions or insight would be greatly appreciated.

• Edited by Gaven LS Thursday, August 08, 2013 5:48 PM

I have the same problem and at the moment I got ~20GB of files in TEMP folder and it's still growing. I wonder why does it happen and is this normal? And can I safely delete content of this folder? Has anybody already tried to delete it ?

• Edited by przemyslawb Tuesday, October 15, 2013 1:11 PM

I'm having the same problem with Exchange 2013 CU7.

The only solution for me right now is doing this procedure once a Month when the mail.queue get to 80-100gigs...

Now run Get-Queue and take a look at the count of messages in HUB01
Goto services.msc and Pause the Microsoft Exchange Transport service
Again, run Get-Queue and ensure all pending messages are zeroed out
Once messages pending becomes zero, stop the Transport service
Move the mail.que file and all others to a new folder in the same location
Start the Transport service
Take a look at the queue again
You should see that messages would have started getting delivered
Now you can backup or safely delete the old mail.que file

I also moved the temp from this file configuration to a fresh new drive to prevent my server to go out of disk space : 

EdgeTransport.exe.config config file under \\Program Files\Microsoft\Exchange Server\V15\Bin

<add key="QueueDatabasePath" value="T:\Queue" />
<add key="QueueDatabaseLoggingPath" value="T:\Queue" />
<add key="TemporaryStoragePath" value="T:\Temp" />

I upgraded to CU8 over the weekend and my Temp Folder is not filling up anymore.

I have moved all files to a different Drive dated before April 1st.

thus far all is good.

Every once in a while I will see TMP files 0KB in size show up in there and then disappear on their own.

So I think MS fixed it in CU8.