Exchange Public Folder Mount Error

Another Exchange specific issue: we had a problem after migrating to Exchange 2010 and then uninstalling Exchange 2003, eventhough replicas of public folders were moved to the new server. Errors would show in the Exchange System Manager, and the following message would occur:
MapiExceptionADPropertyError: Unable to mount database. (hr=0x80004005, ec=2418)

There is a excellent post on TechNet Forums about this topic. However, it does not include information for Exchange 2010, and mentions to restart the Information Store, when restarting the System Attendant is sufficient. Corrected instructions below.

Open ADSI Edit, connect to a Domain Controller, change the context to Configuration.

Create the Folder Hierarchies under the Exchange Administrative Group

  1. Navigate to Configuration ⇒ Services ⇒ Microsoft Exchange ⇒ <Exchange Organization> ⇒ Administrative Groups
  2. Right click on <Exchange Administrative Group> and select New Object
  3. Select msExchPublicFolderTreeContainer as class and click Next
  4. Enter the following as value: Folder Hierarchies, click Next, Finish

Create the Public Folders Tree Object

  1. Right click Folder Hierarchies and select New Object
  2. Select msExchPFTree as class, click Next
  3. Enter the following as value: Public Folders, click Next
  4. Click on More Attributes button, select msExchPFTreeType and set the value to 1
  5. Click OK, Finish

Populate the msExchOwningPFTreeBL attribute object of the PF Store

  1. Double click the newly created “Public Folders” object
  2. Double click distinguishedName, copy the value to the clipboard, click Cancel
  3. Exchange 2007: open properties of Configuration ⇒ Services ⇒ Microsoft Exchange ⇒ <Exchange Organization> ⇒ Administrative Groups ⇒ <Exchange 2007 Administrative Group> ⇒ Servers ⇒ <Affected Exchange Server> ⇒ Information Store ⇒ <Storage Group> ⇒ <Public Folder Database>
  4. Exchange 2010: open properties of Configuration ⇒ Services ⇒ Microsoft Exchange ⇒ <Exchange Organization> ⇒ Administrative Groups ⇒ <Exchange 2010 Administrative Group> ⇒ Databases ⇒ <Public Folder Database>
  5. Double click the msExchOwningPFTree attribute, paste the value that was copied to the clipboard in step 2
  6. Click OK twice

Try to mount the Store

  1. Restart the Microsoft Exchange System Attendant Service
  2. Open Exchange System Manager and try to mount the PF store

53 thoughts on “Exchange Public Folder Mount Error”

  1. Thanks, this worked! Out of the blue the msExchOwningPFTree item was “not set”. Pasted the value, restart system attendant and I could mount succesfully.

  2. I’ve just removed an Exchange 2007 server from my org and public folders failed on the remaining 2010 server. Fortunately your article has saved me from a serious flaming! Many thanks. :)

  3. I apprecitate to this posting.

    Our Ex2007 had a same symptoms and it`s gone by applying this recipe!! :)

  4. Thank you for this article. Worked perfectly and allowed my public folder store in Exchange 2010 to mount straight away.

  5. Hello, I can not find the msExchOwningPFTree attribute.

    I have played with the filters, but still not showing up.

  6. Wanted to say THANK YOU very much as well. After removing our old Exch 2003 suddenly our PF’s went down and I was frantic. This solved it!

  7. If you dont see the msExchOwningPFTree attribute then you’re looking at the wrong object.

    When looking at Administrative Groups ⇒ Databases ⇒ CN=Your Public Folders Database, dont look at the properties of CN=Public Folders object in the right pane, look at the properties of the CN=Your Public Folders Database object in the left pane. You’ll find the attribute there. I made the same mistake myself.

    AWESOME article. Saved my day.

  8. Paul Sterley

    This worked well for me and my PFs are mounted. However, when I open the Public Folder Management Console, I get this error:

    Couldn’t find a MAPI public folder tree. It was running the command ‘get-publicfolder -getchildren -identity ‘\’ -server ‘myserver.mydomain.local”

    Any ideas?

  9. Paul Sterley

    Update: I found a post here:

    This cleared up my problem with the PF Management Console in the Toolbox. You may wish to update your post with the correct information below.

    Microsoft Contingent Staff, Moderator

    After compared the setting in the lab, I found that the class of “Folder Hierarchies” shall be “msExchclassContainer” instead of “msExchPublicFolderTreeContainer”

  10. Good work, you saved my life!!!
    My Boss would kill me, if we loose 12GB PF Data…

  11. Thank you for the fix.

    Very straight forward guide. You should write KB articles for a living :)

  12. Thanks for this article. It worked. I would be happy, if i could see empty public folders, but suddenly old folders also appeared, which was even better.

  13. Dude!! Very much appreciated I was searching for the string to populate the field but didnt know where to get it!!

    Thanks much!!

  14. thank you very much for the info,
    it helped me a lot after searching about last 3 hours a solution for it.


  15. Holy fishsticks! It worked like a charm. I tell you, it’s a dark place over there, in the bowels of the AD.

    Thanks man!

  16. This is great!! It works fine. I had to change the filter to see the msExchOwningPFTree.


  17. Great artikle, was able to get the PF up and running in no time with these instructions.

    The issue had occurred after doing a manual uninstall of an old Exchange 2003 server. This server could not be uninstalled due to the PF aswell.

  18. This article just saved me my life, thanks to God ! and thanks AlanD and the writer of the article !!

  19. Thanks a million this one just saved my life, i had been searching for hours on this

  20. Dude, you rock! I have been looking for a solution to this problem for hours. I stumbled upon your easy walkthru and it worked perfectly! I owe you a beer!

  21. dude Awesome post and saved me hours today. SBS2011 migration from SBS2003, Exchange 2010 fixed. Public Folders are now visable.


  22. This was a great fix! Thanks for your help! Had upgraded from Exchange 2003 to 2010 and this resolved the public folder mount issue.

  23. My issue was slightly different but stemmed from a 2003-2010 migration. PF worked but noticed, after a few weeks had passed, that they weren’t showing in OWA. Followed instructions above and all working perfectly.

    Many Thanks!

  24. Thanks! Worked straight away, i was able to moun public folders.
    This occurred after starting the clean up a very old 2003 sbs server i found still in ad but decommissioned.

    Only found it after we removed the Sites and services references to it, and upgraded schema to 2008 R2 – We were having random crashes of exchange 2010 services. Found that we had missed cleaning up the exchange details in adsiedit.
    Your information was the missing piece of the puzzle. Thanks you again!!

  25. This worked like a charm!!!!

    Appreciate you precise instructions

    Tony B

Leave a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Scroll to Top