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Exchange 2013 Shared mailbox folders dissapearing

Hi there,

At a customer of ours we migrated from Exchange 2010 to Exchange 2013 successfully. Well that is until the following problem showed up:
All clients are running Outlook 2013. All users have a personal e-mail box and they share several shared mailboxes.

Lets call the mailbox Sales@. This mailbox is shared by a lot of users and all the sales related e-mail is kept in separate folders and sub-folders. Up until Exch2013 all was working fine. But after we migrated the shared folders, people started noticing that:

- During the day randomly at random users, the shared mailbox closed it's tree. Not a real problem, cause you can reopen it, but non the less very irritating. specially when it happens very often. We noticed this occurred mostly when people were not using outlook for a few minutes.

- During the day randomly at random users, the shared mailbox folder list would partially disappear. Whole parts of the mailbox wouldn't be shown. Even when the tree would be closed and reopened. Only thing that seems to fix this issue is closing Outlook 2013 and restarting it. We also noticed we could use the "reconnect" option in the "connection status" screen when you <ctrl>+richt-click on the Outlook tray icon. The reconnect also would re-show the whole folder list.

I've been browsing the internet for any permanent fix. I found some mentions about the cache mode, but the users don't have caching on in their profiles. For a test we turned on caching at one of the users for the private mailbox online. But that didn't help. Turning cache mode on for the shared folder isn't an option. This folder is about 13GB in size and that would mean all users (Remote Desktop profiles) would have a 13GB+ .ost file in the terminal server. Since we have over 40 users using this shared folder, we don't think this would help us :-)

Please can anyone help us. Any suggestion would be great.


Joost Groot
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Dejan VasiljevicSys Admin and Programmer

Hi Joost,

If I were You, I would recreate one of the profiles in outlook and test it for one day.
Because I guess it is related to public folders migration to 2013 which is the most difficult and most detailed part of migration, and almost 50% or migrations to 2013 have similar issues and are forcing You to recreate profiles because of stupid little issues/bugs that Microsoft left behind.

Thanks for the quick reply. We alread recreated some of the profiles, because we were having problems with a notification that was keep popping up. The notification was that the "administrator had made changes to the mailbox and outlook needed to restart".

After recreating some of the outlook profiles this problem went away. Though the foldertree of the shared folder stayed or atleast the some of the users with new profiles kept on mentioning this.

I will however re-check it.
Dejan VasiljevicSys Admin and Programmer


Ok, I will wait for Your reply. Meanwhile I will do a small research online.
Satya PathakDomain Architect

This is a known issue after migration .

There is two way to resolve this issue :

Steps 1 : Try to check with online mode once folder is visibal in online mode swhich outlook to cached mode

Steps 2 :  try to remove a user permission and restart outlook and try to add the same permisson and check it
Dejan VasiljevicSys Admin and Programmer

Step 1 will not work for Joost, because he explained that he is not using cached mode, and he will not use it, because it is taking to much space on machine.
As a test I have contacted one user where this problem frequently occurs. I have removed the Outlook profile and even deleted the Appdata\roaming\Microsoft\Outlook and Appdata\local\Microsoft\Outlook folder. Just to be sure everything related to Outlook is as if the user is "new".

I will get back to this threat when I have any news.

I have deleted the \outlook\ folder in appdata\roaming and appdata\local\. I removed the outlook profile. Recreated the profile for the user. Added the shared folder via Advanced options (auto add is turned of).

Within a day the user reported the following:

< I was in outlook doing "nothing" when I noticed the whole tree of the shared mailbox collapsed again. I also noticed that the "favorites" to folders in the shared mailbox were gone. To report this I started a new e-mail and after sending this the shared mailbox recovered it self. It hasn't done this before. All sub-folders were still collapsed, but all root folders were visible. >

So the user didn't have to restart Outlook to get the folder tree back. So halfway there in my opinion. I have a feeling the mailbox collapse is because of some connection threshold in exchange. Does anyone know of any thresholds for connections to shared mailboxes? or even Database connection limits? And ofcourse the question: Why isn't this happening to the personal mailbox?

Does anyone have any idea?
We have abandoned this problem.
No other solutions worked and we abandoned the issue.