XADM: How to Adjust Message Timeouts for the Exchange MTA

• Microsoft Exchange Server, version 5.5

IMPORTANT: This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore it if a problem occurs. For information about how to do this, view the "Restoring the Registry" Help topic in Regedit.exe or the "Restoring a Registry Key" Help topic in Regedt32.exe.

SUMMARY

The Microsoft Exchange Server message transfer agent (MTA) by default will hold messages based on priority for a set amount of time before sending them back to the originator as undeliverable.

These default times include:

   Urgent - 2 days
   Normal - 7 Days
   Non-urgent - 10 days

MORE INFORMATION

The default message timeout values for the MTA are effective in most usage scenarios of Exchange Server; however, there are times when the Exchange administrator will need to increase the timeout values for slow network links or server outages or to decrease these values in the case of highly important and time-sensitive material.

To adjust these settings, do the following:

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys And Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it.

1. Open the Windows NT registry using the REGEDIT utility.

2. Go to the following key:

         HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services
         \MSExchangeMTA\Parameters
   

3. Select Edit.

1. Make a new entry for each one of the following timeout categories:

         Message timeout (urgent), minutes
         Message timeout (normal), minutes
         Message timeout (non-urgent), minutes
   

   These must be typed exactly as they appear above. They can be individually entered or all used.

2. After the new key is created, enter the desired timeout as expressed in minutes. This can be anything from 1 to 65536.

   An example would be to set normal messages to time out in 14 days. This would be entered as 20160.

   The maximum timeout value is 45 days.