Tech Blog

Had a very weird issue where users on prem couldnt access mailboxes for users online even though the permissions were correct.

The error was:

Cannot expand the folder. The set of folders cannot be opened.

Had a good google and the recommendations were to do the following which didnt work for me:

Connect to 365 and run:

#remove permissions
Remove-MailboxPermission -Identity Manager@bohemiangrove.co.uk -User User1@bohemiangrove.co.uk -AccessRights FullAccess

#Add permissions
Add-MailboxPermission -Identity Manager@bohemiangrove.co.uk -User User1@bohemiangrove.co.uk -AccessRights FullAccess -InheritanceType All -AutoMapping:$false

So what I did to fix this was to add this for

1. Exit Outlook.
2. Start Registry Editor. To do this, use one of the following procedures, as appropriate for your version of Windows:
3. In Registry Editor, locate and then click the following registry subkey:
   HKEY_CURRENT_USER\Software\Microsoft\Exchange
4. On the Edit menu, point to New, and then click DWORD Value.
5. Type AlwaysUseMSOAuthForAutoDiscover, and then press Enter.
6. Right-click AlwaysUseMSOAuthForAutoDiscover, and then click Modify.
7. In the Value data box, type 1, and then click OK.
8. Exit Registry Editor.

Before I get started this is not referring to standard Distribution Groups, this email refers to the groups that can be created in the newer version of Office 365 that allow a “Lync-esque” conversation feature but with added functionality, such as reviewing previous messages when added at a later date.

In most environments this would be a great feature, workplace and alike, however in environments like  schools it can lead to some administrative troubles as there is no, current, way to administrate the groups once created as they are hidden to the admin unless viewed within the mailbox/OWA of the user doing the creating.

In this particular case these groups needed to be, A: removed manually, and B: disabled from future creation.

First you have to log in to the exchange mailbox via PowerShell, so have your admin credentials ready, once you are in and are ready to make changes, this is the command to run;

Set-OwaMailboxPolicy -Identity <strong>DOMAIN.LOCAL</strong>\OwaMailboxPolicy-Default -GroupCreationEnabled $false

You can create a new policy and apply the above change to it, then set that policy as the default for your users/groups.

Please see this article for a much more in-depth overview of the feature and how to disable or utilize it.

If you have any questions please email me.