Create a Shared Mailbox from a new Synced User Account

Question

Is there any way to create a shared mailbox in Office 365, linked to a new synced user account ?

I mean:

1. Create a new user account in Active directory.
2. Sync it to office 365 (Azure AD connect)
3. Set this new synced user account to be a shared mailbox.

Many thanks

Edit to add more info / *** re-edited to update the procedure ****

The only approach I found is first add a Exchange license to the new synced account, and then convert the mailbox to a shared mailbox. But I feel like there's should be a more efficient way to achieve it. This are the steps of this approach:

1. In the 365 admin portal select the new synced user account, for example :

   shared.mailbox.Sales@mydomain.com

2. Add an available exchange license, for example :

   Exchange online Plan 1

3. Convert the mailbox to be a shared mailbox with the cmdlet set-mailbox :

   get-mailbox shared.mailbox.Sales | set-mailbox -type shared

4. Since a shared mailbox don't require a license, you can remove the previously assigned license in the admin 365 admin portal.

The pro's to have the shared mailbox linked to an AD synced account are:

• You have all your accounts in your on premise Active Directory.
• In case you need the shared mailbox to be accessed using a user/password, you can use the active directory user/password and access to it using outlook.office365.com

sources: http://office365support.ca/create-a-shared-mailbox-from-an-existing-synced-user-account/ https://answers.microsoft.com/en-us/msoffice/forum/msoffice_outlook/service-accounts-shared-mailbox-with-enabled/0243cceb-35ee-4fed-88b4-908054a95578

Answer 1

Will you need to manage a lot of these mailboxes? Do you have any Exchange on-prem servers?

An option is to create and manage these mailboxes completely in Office 365. Is there a specific need to have them exist in your AD?

As you've seen, you need to create a licensed mailbox, before you can convert it. To get around this, you can try the "Enable-RemoteMailbox" PowerShell command, and use the "-Room" switch.

https://technet.microsoft.com/en-us/library/ff607313(v=exchg.150).aspx The Enable-RemoteMailbox cmdlet mail-enables an existing on-premises user. The mail-enabled user contains a specific attribute that indicates that an associated mailbox in the service should be created when the user is synchronized to the service using directory synchronization.

This article also describes what you want to do, but seems a bit wonky: https://365lab.net/2014/06/20/exchange-online-how-to-create-a-dirsynced-resource-mailbox/