We have a hyrbid environment setup between Exchange 2010 and O365 for both mailboxes and Public Folders. Since putting Public Folders in hyrbid mode (through use of https://docs.microsoft.com/en-us/exchange/collaboration-exo/public-folders/set-up-legacy-hybrid-public-folders ) we keep getting reports every export cycle containing the below for a couple of our mail enabled Public Folders:

Unable to update this object because the following attributes associated with this object have values that may already be associated with another object in your local directory services: [ProxyAddresses smtp:<interal e-mail address>;]. Correct or remove the duplicate values in your local directory. Please refer to http://support.microsoft.com/kb/2647098 for more information on identifying objects with duplicate attribute values.

With AD Users & Computers not listing much for Public Folders objects stored in the OU Microsoft Exchange Systems Objects (specifically the Attribute Editor), seemingly no way to advanced search for "contains" in the proxy address attributes in AD Users & Computers, Public Folder management console in Exchange 2010 not having an Attribute editor, and ADSI Edit seemingly not having a search function, not sure how one is to go about finding which AD object has a duplicate SMTP address in proxy address'. Anyone else have some ideas?


have you tried the methods in the link below?

Duplicate or invalid attributes prevent directory synchronization in Office 365 https://support.microsoft.com/en-hk/help/2647098/duplicate-or-invalid-attributes-prevent-directory-synchronization-in-o

  • I have... Method 1 yielded nothing about the supposed duplicate records; Method 2 doesn't apply as the objects in question were on-prem, first; Method 3 I can't use, because Exchange 2010 Public Folders (at least seen through ADSI edit) don't appear to have UPN's. Trying to use the -searchstring method of get-msoluser (with the Distinguished Name of the object), including the $_.LastDirSyncTime property returns nothing, and finally using get-msoluser -all | where {$.LastDirSyncTime -eq $null} returns a whole bunch of users, none of which is the user in question – user66001 Feb 22 '19 at 17:33

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