The following errors may be logged in an environment that has been upgraded to a new version of Exchange (usually 2003 to 2010), or a service pack to Exchange (2010) has been installed.

MSExchange ADAccess Event ID 2937

Log Name: Application
Source: MSExchange ADAccess
Date: 9/26/2010 9:12:29 AM
Event ID: 2937
Task Category: Validation
Level: Warning
Keywords: Classic
User: N/A
Computer: server.contoso.com

The reason for this error is that an AD attribute of an item (e.g. mailbox, connector, routing group, etc) is pointing to the DN of a server which has recently been deleted from AD. As long as the object is still physically present in AD (i.e. it has not been purged yet), this will not directly pose a problem, but as soon as it's gone forever, this may cause all sorts of trouble with one or more components of Exchange, depending on the object.

Most commonly, there are two types of errors that can occur, each with their own solutions.

First things first

First and foremost, check whether the deleted object really had to be deleted. If not, it is recommended to immediately restore the object in AD.

However, if the deleted object is supposed to be deleted, then we only have to fix the references to the deleted object so it points to the correct one.

[HomeMTA]

The most common occurence for this error is an incorrect value for the [HomeMTA] attribute, which is still pointing to an old mailbox server. In that case, the following error is logged:

Event ID 2937 for [HomeMTA]

Process w3wp.exe () (PID=1960). Object [CN=My User,CN=Users,DC=domain,DC=com]. Property [HomeMTA] is set to value [companyabc.com/Configuration/Deleted Objects/Microsoft MTA DEL:0a058a00-f3ed-1457-ba80-417d4e7dfc44], it is pointing to the Deleted Objects container in Active Directory. This property should be fixed as soon as possible.

In this case, you can fix this issue through EMS.

Get-Mailbox "MyUser" | Update-Recipient

Get-Mailbox | Update-Recipient

Get-Mailbox -Arbitration | Update-Recipient

[RoutingMasterDN]

Another common occurence is the Edge Transport routing group property. The following event is logged:

Event ID 2937 for [RoutingMasterDN]

Process edgetransport.exe () (PID=3500). Object [Exchange Routing Group (FYDIBOHF23SPDLT)]. Property [RoutingMasterDN] is set to value [exedge\0ADEL:a17b2d49-9f49-411e-be06-a9f49f864be0], it is pointing to the Deleted Objects container in Active Directory. This property should be fixed as soon as possible.

This problem can be corrected with ADSI Edit:

1. Start ADSI Edit and connect to the Configuration namespace of your domain. You need domain admin privileges in order to do so.
2. Navigate to:
   CN=Servers,CN=Exchange Administrative Group (FYDIBOHF23SPDLT),CN=Administrative Groups,CN=Contoso,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=contoso,DC=com
   Replace parts of the DN part according to your domain.
3. Right-click the Edge Transport server and copy its distinguishedName value (completely!)
4. Navigate to:
   CN=Exchange Routing Group (DWBGZMFD01QNBJR),CN=Routing Groups,CN=Exchange Administrative Group (FYDIBOHF23SPDLT),CN=Administrative Groups,CN=Contoso,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=contoso,DC=com
   Again, replace the correct parts in the DN.
5. Right-click the object, then click Properties.
   In the attributes list, locate the attribute msExchRoutingMasterDN and edit to replace its value with the DN copied in step 3.
6. Restart the Transport service.