Adding Mailbox Folder Permission for a User

Iron Contributor

I'm an Office 365 administrator, and sometimes I get a request to share a mailbox folder for a user. For instance, a manager may request access to the inbox of a team member to review emails during their vacation. In this case I would typically use Add-MailboxFolderPermission to grant Reviewer access to the inbox folder for the user:


Add-MailboxFolderPermission -Identity "frodo baggins:\inbox" -User "bilbo baggins" -AccessRights Reviewer

It seems that most times when I do this, it takes hours or days for Outlook 2016 to actually let the manager access the mailbox folder. The employee's mailbox does not automap into Outlook and manually opening the mailbox in the account settings adds the entry, but Outlook complains that it can't open the folder. Sometimes this starts working on it's own after several hours or the next day, but sometimes it seems to never work at all. If this is a time-sensitive request this doesn't work.


Recently I worked around this issue by granting full access to the mailbox which seemed to take place immediately and the mailbox auto mapped into Outlook. However, it's not always desirable to grant this level of access.


Is there something I am missing about how mailbox folder permissions can be granted by an administrator? Is there a workaround to get a shared folder showing up in Outlook more quickly? Thanks!

4 Replies

No, you're using the correct approach, it simply takes some time to replicate the changes. Dont forget to add access on the "top on information store" folder as well though. Full access permissions are also not instantaneous, I've had occasions that it took almost a day for them to apply. Oh, and there's no automapping when you grant folder level access, you have to add it manually in Outlook.

I checked on the "Top of information store" thing, and when a user has shared a folder via Outlook, there are no additional permissions configured there. Do you think I should run Add-MailboxFolderPermission on both the inbox folder and the top level when I do this? Should I just add FolderVisible there?


I believe I have tried this method in the past and it didn't have any effect, but I can't confirm that.


Anyway, thanks for confirming what I believed to be the case - that the real problem is simply with propagation across the Exchange environment. I believe I'll need to come up with a process that we can follow in these cases where immediate access is needed. Do you think that advising the users to open the shared folder in OWA would be a workaround, or would the permission propagation still be an issue?


As always, thanks Vasil!

"FolderVisible" on the top of information store is required for older versions of Outlook to display the shared fodlers properly, OWA doesnt seem to have a problem with it missing though. It's not the issue in your case, just something to be mindful about.


You can try OWA in your case, I dont think it will make much of a difference.

@Matt McNabb 

You can use the Exchange Online PowerShell cmdlets like Add-MailboxFolderPermission, Get-MailboxFolderPermission, Get-MailboxCalendarFolder, Set-MailboxFolderPermission and Remove-MailboxFolderPermission. For more details on mailbox folder management, go through the below blog: