In environments which have migrated from Exchange 2010 to 2013 (or later), and where public folders have been decommissioned, you may encounter the following events in the Application event log:

MSExchange ADAccess, Event ID: 2937

Process MSExchangeTransport.exe (PID=9356). Object [CN=Contoso,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=contoso,DC=com]. Property [RemotePublicFolderMailboxes] is set to value [contoso.com/Deleted Objects/PublicFolderMailbox DEL:d980f9a4-2014-4165-aad0-7ab91b35ef01], it is pointing to the Deleted Objects container in Active Directory. This property should be fixed as soon as possible.

With the removal of the public folders database, not all objects referencing the database have been adjusted. You can manually fix the issue by clearing the reference to the deleted public folders database, using ADSI Edit.

1. As a domain admin, open ADSI Edit (adsiedit.msc).
2. Connect to the Configuration well-known naming context of the domain in which Exchange operates.
3. Navigate to the object mentioned in the warning event (in this case: CN=Contoso,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=contoso,DC=com).
4. Right-click the object itself (not any of the subordinates) and click Properties.
5. Browse the attributes of the object. One of the attributes should mention the deleted public folder database. Clear the value. If more than one public folder database was used, clear all of them, unless you still have a public folder database in use, in which case you should leave the references to the existing databases as is.
   Note that the Property mentioned in the event does not always match the name of the attribute in AD. In our example, the property RemotePublicFolderMailboxes (retrievable through EMS: Get-OrganizationConfig | Select RemotePublicFolderMailboxes) is in fact the attribute named pFContacts).
6. After clearing the incorrect values, the event should no longer be triggered. Note that multiple references may exist. Clear the invalid references of all the objects to get rid of the events.

As the change is in AD, clearing the values should only be done on one DC. The change will be replicated to all DCs and all Exchange servers will pick this up.