After a user quit, an administrator wanted to convert the mailbox to a shared mailbox, to free up the license the mailbox was using. Because the user handled important communications, he didn’t want to delete the mailbox right away.
While I’d export the mailbox to a pst for backup, delete it and add the user’s address(es) to the mailbox of the person who took over the job, it is possible to convert a mailbox to a shared mailbox.
Shared mailboxes in the Business and Exchange Online Plan 1 and Plan 2 have a quota of 50 GB.
A license is not required for a shared mailbox provided you do not enable In-place Archive. If you are converting a user mailbox with an In-place archive to a shared mailbox, you'll need export the archive to a pst before converting the mailbox.
Both on-prem Exchange and Office 365 Mailboxes can be converted to shared either using PowerShell or using the Exchange Admin Center.
Using the Admin Center
To convert mailboxes using the web interface, open the Office 365 Admin center in your browser. Select Users then select the mailbox you need to convert.
It will take a few minutes to convert the mailbox to shared. Once finished, remove the license from the mailbox in the Office 365 Admin center. Select the account again, then click Edit to the right of Product licenses. Slide the license indicator to Off then click Save.
Using PowerShell
If you are comfortable using Powershell, you can use the Set-Mailbox cmdlet to convert a mailbox to a shared mailbox.
Set-Mailbox info@domain.com -Type shared
If desired, you can change the quota before setting the mailbox to shared.
Set-Mailbox info@domain.com -Type shared -ProhibitSendReceiveQuota 10GB -ProhibitSendQuota 9.5GB -IssueWarningQuota 9GB Set-Mailbox info@domain.com -Type shared
The Type parameter supports Regular, Room, Equipment, and Shared as values.
Verify the mailbox is now a shared mailbox:
Get-Mailbox -Identity info@domain.com | Format-List RecipientTypeDetails
To create a list of all users and mailbox types to a csv file, use this cmdlet. Name returns the display name; you can use alias instead (or add alias as another field).
Get-Mailbox | Select-Object name,RecipientTypeDetails| Sort-Object name| export-csv D:\Documents\output.csv
After converting the mailbox, give other users Full Access and Send As permission as needed. You can do this from the Exchange Control Panel or using PowerShell.
To use PowerShell to give a user or group FullAccess rights:
Add-MailboxPermission username -User newuser -AccessRights FullAccess
To use PowerShell to give a user or group SendAs rights:
Add-RecipientPermission username -Trustee newuser -AccessRights SendAs
Now you can remove the license from the account in Users and Groups. Two dialogs will warn you that removing the license will delete the mailbox and the contents, however, because you converted the mailbox to a shared mailbox before removing the license, the mailbox won't be deleted. Note: while the mailbox contents are safe, Lync contacts may be lost.
The first dialog:
The second dialog reads:
Are you sure you want to remove the Exchange license?
The user’s mailbox and all messages in it are deleted. We recommend that you only delete licenses from users who no longer need email.
All email aliases associated with the user account are deleted. If you need someone in your company to receive email at those aliases, assign them to another user.
Their Lync Contacts list may be deleted. To restore their Lync Contacts, assign the user an Exchange license within 30 days. If you want to remove their Exchange license but keep their Lync Contacts, contact Support before you remove the Exchange license.
More Information
More information is available at Convert a Mailbox (TechNet)
Shawn says
What would cause a User Mailbox that was converted to a Shared Mailbox using EAC to not show up in the Shared Mailboxes section and the User to still exist in the Mailboxes Section. After running the Convert link on the User that we want as a Shared Mailbox
Nath says
This is a known issue when using Microsoft Partner logins.
Alex says
What if I want to convert a "user" (=UPN without a license) not a usermailbox to a shared mailbox?
Diane Poremsky says
This is a contact? I think you will need to remove the contact from the gal then add the address back as a shared mailbox.
This powershell converts a mailbox to a user, but i didn't see one to convert a user to mailbox.
https://gallery.technet.microsoft.com/office/How-to-convert-mailbox-to-c92c9153
rino19ny says
i have Exchange 2013 cu17, i don't see that convert option in the ECP.
Diane Poremsky says
I don't have an Exchange 2013 ECP handy to double check, but if they it's similar to the new Office 365 interface, it was moved to the main user admin screen (where you assign licenses and reset password). Select the user, expand the mail section - convert to shared is at the bottom.
You can always use a cmdlet: Set-Mailbox alias -Type shared
https://technet.microsoft.com/en-us/library/bb123981(v=exchg.150).aspx
Kevin says
All, I have several mailboxes the need to be converted to shared mailboxes. First, I want to run a script that will verify the type of mailbox it is. I would like to import a CSV file and have the script tell me what each mailbox type it is. 2nd, I would then create another CSV file and import the contents into a 2nd script that would convert the mailboxes to a shared mailbox.
Help please, Thanks
Diane Poremsky says
I know you can do the first... and use a csv to convert the listed accounts to shared, but I 'm not sure you can pipe it into set-mailbox (it's not working here, but I'm not a powershell expert, so it could be user error :))
To get a CSV, use this cmdlet:
Get-Mailbox | Select-Object name,RecipientTypeDetails| Sort-Object name| export-csv D:\Documents\output.csv
if you want more fields, see https://technet.microsoft.com/en-us/library/bb123685(v=exchg.160).aspx
using the csv to do something would be something like this:import-Csv D:\Documents\output.csv | ForEach-Object { Set-Mailbox -Identity $_."name" -type shared}
Victoria says
How can I move an Exchange shared calendar to Office 365 as a shared calendar?
Diane Poremsky says
You (or someone with the right permission) needs to create the caendar in office 365 then use a list view to select all, copy and paste to the new calendar.
Earle Maharaj says
We've been converting user mailboxes to shared for at least 6 months now. The users with rights to the shared mailboxes are reporting that the shared mailboxes are no longer receiving new emails. Is there another setting in console that needs to be enabled for converted user to shared mailbox to receive email?
A-FS says
Can external users be members of shared mailboxes? How would they access the shared mailbox?
Diane Poremsky says
If you create a mail contact, they get a password and an internal address (but no mailbox) then assign their user contact full access permission to the mailbox, they can log into Outlook on the web using the internal address and password - address would be https://owa.domain.com/owa/sharedmailbox@domain.com/. It can take some time for the permissions to propagate.
You can't use Outlook on the desktop, on the web interface.
It can take about 15 minutes for permissions to update after adding the contact to the shared mailbox.
Michael says
Nice article!
How do you create a mail contact that gets a password?
Stephan says
Thank you for the article. Converting the mailbox is really simple. However, I cannot find the option to remove the license from the AD account. We have a local server, not online. Any ideas?
Diane Poremsky says
Is everything on the local server or it is a hybrid configuration?
This removes an E3 from an account
Set-MsolUserLicense -UserPrincipalName alias -RemoveLicenses "company-name:ENTERPRISEPACK"
verify it was removed using
Get-MsolUser -UserPrincipalName alias
More information https://technet.microsoft.com/en-us/library/dn771774.aspx
Bobby says
I follow the Powershell method to convert user mailboxes to shared if a terminated user's email needs to be retained for a while. However, when I do this, and then go to AD to disable the user account, after a DIRSYNC the user and shared mailbox both disappear in o365. Am I forgetting something?
Diane Poremsky says
Don't disable the account - remove the license after changing it to shared.
Janos says
Using Office 365 Enterprise E3, now the Admin Center is different.
There is no Recipients, But USERS/Active Users. But the main problem, there is no "Convert to Shared Mailbox" choice!
Where is it in this new Admin Center?
Diane Poremsky says
Are you in the Exchange admin portion? https://outlook.office365.com/ecp/?rfr=Admin_o365&exsvurl=1&mkt=en-US&Realm=yourdomain
Andy Mayle says
Having made the mistake of deleting AD users that had left as part of a clean up process, I discovered that all their mailboxes that had been converted to shared were also deleted. I discovered an easy fix. Go to Users > Deleted Users and restore the account as a cloud account. No need to apply a license. The shared mailbox reappears after a time with full content and all permissions restored. It keep the AD clean but the user account does have to exist in the cloud.
Diane Poremsky says
Yeah, you need to keep the AD account but can delete the license after converting it to a shared mailbox.
Boyejo Ayoola says
Hi,
Since it's not possible to log in to a shared mailbox, I would like to set an automatic response for the account so external contacts can know that the user has left the firm. I do I go about this?
Diane Poremsky says
Assign permission to the mailbox to your account then create a new profile for the shared mailbox. See https://www.slipstick.com/exchange/create-rules-and-oof-shared-mailbox/ for details.
BenMarshall says
Hi Boyejo
To set an out of office auto responce for a shared mailbox from the exchange online admin centre select your user tile (top right) then select open another mailbox... Type the shared mailbox name and press OK.
This will load the mailbox preferences for the shared mailbox and you can define any rules / out of office.
Thanks Ben
Dhiraj pandey says
what is limitation shared mailbox conversion?
Diane Poremsky says
I'm not aware of a limitation either in the number of shared mailboxes you can have or the number of people who have access rights to a mailbox.
Dhiraj pandey says
Dear all,
after some users convert E3 to shared mailbox successfully but convert 91 users, conversion stop and no error message shown?
Dhiraj
ac says
Would a local AD account need to be kept in order to keep using the shared or resource mailbox?
Diane Poremsky says
Shared and resource mailboxes will have a disabled AD account, so yes, it needs to be kept.
Pete Belcher says
So to clarify, for every user who leaves the business, I can convert them to a Shared Mailbox and keep the data indefinitely, this is OK and doesn't breach the license agreement?
I would have thought this is using the shared mailbox feature as effectively archiving/backing up the users email and data permanently without paying for it.
Diane Poremsky says
Correct, you can convert it to shared (and remove the license) and keep it without breaching the license agreement. It's really no different than using public folders (which in newer version of Exchange are mailboxes too).
Pete Belcher says
Thanks for the prompt responses, I am surprised, seems like a way to cheat the system.
Diane Poremsky says
Cheating the system is buying 1 mailbox and creating shared mailboxes for active employees to use (with everyone using the same account to log into their own mailboxes). :) In your case, you are just keeping the former employees mailbox around for historical purposes, possibly because its covered by a law that says it must be kept. It's really no different than a generic sales@ or support@ address that is typically a shared mailbox.
Pete Belcher says
What is the legality of this? does it not breach the license agreement? I would think using Shared Mailboxes as a way to effectively archive is not allowed?
Diane Poremsky says
The legality of converting mailboxes to shared and removing the license? It's legal - you lose the ability to log into it directly, only accounts with permission can access it. You can't automatically archive to it - you'd need to drag and drop mail into it. It also can't have an online archive mailbox, that feature requires a license.
Some of the comments are asking about converting a licensed mailbox that has an online archive to shared - the online archive needs to be exported to a pst, the mailbox converted and the pst imported. Otherwise, the contents of the online archive are lost.
At one time an unlicensed shared mailbox had a lower quota (5 GB) but Microsoft recently removed that requirement and they now have the same 50 GB available to licensed mailboxes.
Jon R says
is there a good way to move the archive emails back into the primary mailbox, or is it a manual process thru an Outlook client?
Diane Poremsky says
Archived to a pst or to the online archive mailbox?
Online archive mailbox: either move them yourself or export to a pst then import into the mailbox.
PST: You can import or just keep them in the archive and open the archive in outlook - file, open, outlook data file.
JD in MN says
I didn't understand that we need to keep shared mailboxes as a user, but not need a license. Delete the license--don't delete from active users.
I was able to remove the license in Exchange Online Admin, after converting to shared mailbox, without using Powershell.
Diane Poremsky says
Yeah, they updated the admin center a few weeks ago to support conversions.
Will Nichols says
The only way to remove the license once converted to shared is through powershell now.
Bob says
For online archive, you need to backup the online archive to a .pst file, create a shared mailbox, export the .pst file to the shared mailbox and you then have the mailarchive of the old user.
My question is though, if we delete the user first (after backing up the email to .pst), and then create a shared mailbox with that uses name, would emails still arrive in the inbox just as if the user is still active?
As I alrady have other shared mailboxes setup that are receiving emails from external users, I am assuming this would be the case?
Diane Poremsky says
The messages would arrive in the shared mailbox if the smtp address was the same as before. you can export the mail to a pst then remove the online archive and switch it to shared. That might be easier than deleting and recreating.
Matthew Marlowe says
This didn't work for me. I converted to Shared, then just removed the license and it deleted the Exchange box. It's gone. ;(
Diane Poremsky says
That's not supposed to happen if you convert to shared before removing the license. Are you using Office 365 or an on premise exchange server?
It should be recoverable for up to 24 hours, if not longer.
Charlie says
That didn't seem to work for me. i converted to Shared, deleted the user, and then it delete the Shared inbox also. Lucky I still took a backup.
Diane Poremsky says
Yeah, you don't delete the user, you only remove the license from their account.
Andy says
Like this Idea. Thanks! However I'd like to rename the mailbox to indicate it is for a former employee, my problem is that the object is synced with AD. I can rename it in AD but at some point the AD object will be deleted and the mailbox won't be. Is there a way to break AD sync for one object.
If not, it's a question of exporting from a user mail box them importing to a shared one. A bit time consuming to say the least. lol.
Diane Poremsky says
AFAIK, there is no way to break the sync with the AD - you need to keep the unlicensed user. You might be able to rename it, but it will still be linked to the AD object.
Frank S. says
I am getting cmd not available when trying to run the Get-Mailbox from powershell?
Diane Poremsky says
which command does it say is the problem? I noticed today that there was a space after one dash - there is not supposed to be a space between the dash and the parameters.
mdelcar007@hotmail.com says
I'm looking to convert a regular mailbox to a shared mailbox and was looking at risks in doing so. I wanted to confirm your 5gb limit for shared mailboxes, but the technet site says 50gb for shared mailboxes on 365 Enterprise. Can you confirm?
Diane Poremsky says
They recently raised the shared quota for a *free* license to 10 GB. You can create a shared mailbox with a higher quota but will need to assign a license to it.Looks like they changed the quota again - it's now 50GB, no license required unless you need online archiving.
Avinash Illindra says
Thanks for the great article, it will be very helpful article.
I have a small doubt on Second dialog:
We lost the mails surely or is there any alteration for without loosing mails.
Regards,
Avinash Illindra
Diane Poremsky says
Unless the mailbox is over 5 GB or is using an online archive, you won't lose any messages. If there is more than 5 GB in the mailbox, the mailbox may be truncated - if you are using an online archive, it will be lost. The mailbox should be recoverable though.
Mike says
great article!!! especially for a novice like me. i do have to say though i am lost at the last part where you say
"Now you can remove the license from the account in Users and Groups."
where is that done? i can't find it
Diane Poremsky says
They keep changing it, but as of this writing, Login to Office 365, select User > Active Users and double click on the account your changes to a shared mailbox. That will open their user account, then click Licenses.
This link should get you there - https://portal.office.com/admin/default.aspx#ActiveUsersPage
Adam says
This was a very useful article, being the first time I've needed to perform such a task. Thank you!