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How to stop Outlook from using Public Folders.

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While working on a case, where Exchange 2010 users randomly get pop-up message:

"The Exchange administrator has made a change that requires you quit and restart
Outlook."

We verify that the affected users have not been moved, and not changes were done on Exchange while
this message pops up.

After a few month of trying to collect data we found that Outlook was trying to contact public folders, and the customer do not really used public folders and we found a registry key that was not documented that is able to stop Outlook from trying to connect to public folders.

Key:

HKCU\Software\Microsoft\Exchange\Setup\

DWORD Value:

HasPublicFolders

HasPublicFolders = 0

After settings this registry key we no longer get reports of users getting the pop up to ask them to restart Outlook, unless the mailbox is really moved.

Since I know that case I have use this key in other situation that help isolate if issue is related to public folder access.

Outlook client applications cannot connect to public folders after you install Exchange Server 2010 SP1
https://support.microsoft.com/kb/2535105

FIX: Application may stop responding after several HTTP requests are aborted if you use the HttpWebRequest class to send requests in the .NET Framework
https://support.microsoft.com/kb/2497453

In KB 2535105, If you are affected you may receive different symptoms such as:

Outlook getting prompted
for credentials

Connection failing over
from TCP/IP (MAPI) to HTTPS (Outlook Anywhere / RPC-HTTP)

High CPU usage on CAS
due to public folder referral

Using the registry key to stop Outlook from using Public folder the Outlook client symptom is workaround. (A good way to isolated if those issues is related to public folder
access.)

If this key help you or other scenario that you find this key helpful please leave a comment.

Thanks,

John

Comments

  • Anonymous
    January 01, 2003
    Very Helpfull Thanks!

  • Anonymous
    April 02, 2013
    Great. It's very helpful!

  • Anonymous
    September 10, 2013
    Hello, thanks for the post. I tried the registry tweak, but Outlook still shows Public Folders in the folder pane. Am I missing something here? I'm using Outlook 2010. Thanks Christian

  • Anonymous
    September 20, 2013
    hey, this doesnt work at all. thanks for wasting my time

  • Anonymous
    December 04, 2013
    This does work ... I had same problem and adding this entry did fix my issue

  • Anonymous
    January 29, 2014
    It does work … but stops working once you reach the later build numbers on Outlook 2010. That is why some on here say it works, and others don't. If anyone knows how to reintroduce this feature in the later versions of Outlook 2010, that would be very helpful as Microsoft have broken Outlook 2010 on Windows XP with Exchange 2013 CU3, turning off Public Folders makes this environment more usable.

  • Anonymous
    January 31, 2014
    Great find. This reg mod saved some frustration for our mobile users. For us, the problem was the constant credential prompts. I added this key to the affected users and life was good again. Thank you for taking your time to post this.

  • Anonymous
    March 12, 2014
    Thanks a lot! We atre currently in an Exchange 2010 (SBS 2011) to 2013 migration. The customer has no PublicFolders at all but after moving user mailboxes to 2013 clients still tried to connect to old PF Store. Perfect workaround that saved me a lot of time.

  • Anonymous
    April 24, 2014
    This works for Outlook 2013.Thanks John for sharing this!

  • Anonymous
    September 22, 2014
    Works great...fixed our problem with Outlook clients looking for public folders

  • Anonymous
    September 22, 2014
    Works great...fixed our problem with Outlook clients looking for public folders. Forgot to add we are using Exchange server 2010 SP3 rollup 6 and Outlook 2013.

  • Anonymous
    January 21, 2015
    Worked for outlook clients in our transitioning exch2007 and exch2013 (CU7) Thanks

  • Anonymous
    January 27, 2015
    Not working for us, Outlook 2013 (15.0.4667.1000)

  • Anonymous
    February 20, 2015
    worked for me as well, however, I would prefer a solution that doesn't include the patching the client.

  • Anonymous
    April 02, 2015
    Working for me nicely .. Exchange 2010 SP3 RU8 and Outlook 2010 32 bit 14.0.7145.5000

  • Anonymous
    June 15, 2015
    Since there are some limitations for Exchange 2013 Public Folders , we will focus this little note on

  • Anonymous
    August 07, 2015
    Thanks a lot, had to create setup - key, but it worked very well.

  • Anonymous
    August 27, 2015
    This worked for me. I deployed the registry entry via a GPO.
    Thanks.

  • Anonymous
    October 12, 2015
    Perfect dude its working well

  • Anonymous
    November 11, 2015
    Thank you very much. It works fine, but I agree with Marshall, it would be nice to have a solution from the server. As a rule, I do not like deploying registry changes wholesale through GPO.

  • Anonymous
    December 03, 2015
    This does not work with Office 365.

  • Anonymous
    December 15, 2015
    I have also tested with E365, does not work.

  • Anonymous
    March 01, 2016
    perfectly working on an exchange 2007/2013 environment with oulook 2010/2013 clients

  • Anonymous
    March 01, 2016
    (thanks John Mak !!!)

  • Anonymous
    October 06, 2016
    Please note that this registry key is not supported officially, use at your own risk.