"Public folder "" couldn‎'t be mail-enabled" error when you try to migrate public folders to Exchange Online

Applies to: Exchange Online


When you try to migrate public folders to Exchange Online, the migration fails and you receive an error message that resembles the following:
MigrationPermanentException: Error: Public folder "/<FolderName>" couldn‎'t be mail-enabled. The error is as follows: "No MailPublicFolder entry was found in Active Directory with OnPremisesObjectId=‎'4a66593b-12b0-4742-9e39-1a7dccd5fc7a‎' or LegacyExchangeDN=‎'/CN=Mail Public Folder/CN=Version_1_0/CN=e71f13d1-0178-42a78c4724206de84a77/CN=000000001A4473 90AA6611CD9BC800AA002FC45A0300E7243831D8E5
0446AB3A0E4E3AEBE23500000000715A0000‎'". This failure can happen when MailPublicFolder objects in Exchange Online are out of sync with your Exchange deployment. You may need to rerun the script Export-MailPublicFoldersForMigration.ps1 on your Exchange server, followed by the script Import-MailPublicFoldersForMigration.ps1 on Exchange Online to update MailPublicFolder objects in Active Directory. 


This problem occurs if the NON_IPM_SUBTREE system folder contains mail-enabled public folders. Public folders in the NON_IPM_SUBTREE folder don't have to be mail-enabled. They may have been previously mail-enabled because they were in a Microsoft Exchange 2000 Server environment that was running in mixed mode. In this situation, Exchange tries to mail-enable all public folders. 


Mail-disable all public folders that are mail-enabled in the NON_IPM_SUBTREE folder. For more information about how to mail-disable a public folder, see Mail-enable or mail-disable a public folder.

To locate the system public folders, open the Exchange Management Console, go to Toolbox, open the Public Folder Management Console, and then expand System Public Folders. Mail-disable any public folder that has a mail icon next to it.


Still need help? Go to Microsoft Community.