Convert a user mailbox to shared in Exchange and Microsoft365 Ranjan.info

Multiple users can access shared mailbox in return. the opposite of a common user mailbox, a shared mailbox account is disabled in Active Directory and cannot be used for interactive sign-in. This article describes how to convert a normal user mailbox to a shared mailbox in on-premises Exchange Server and Microsoft 365.

When you convert a user mailbox to a shared mailbox, only the mailbox type is changed. All existing e-mail messages and calendar items, mailbox and folder permissions, as well as mailbox rules are maintained.

You may need to convert a user mailbox to a shared mailbox when:

• If you want to share a mailbox with multiple users, use a shared calendar when scheduling;
• The user leaves the organization and you want to share the mailbox contents with the remaining employees;
• No separate license is required for a shared mailbox

How to convert a user mailbox to a share on Exchange Server with PowerShell?

In on-premises Exchange Server 2019/2016/2013, you can convert a user mailbox to a shared mailbox by using set-mailbox PowerShell cmdlet. Use the below syntax:

Set-Mailbox -Identity <MailboxIdentity> -Type <Regular | Room | Equipment | Shared>

Open the PowerShell console and connect to your Exchange server. Check mailbox type with command:

Get-Mailbox -Identity a.shepherd| Format-Table Name, RecipientTypeDetails

This is a normal user mailbox (UserMailbox,

To change it to a shared mailbox, run the following command:

Set-Mailbox a.shepherd -Type Shared

The mailbox type has changed to SharedMailbox.

To convert multiple user mailboxes to shared mailboxes at once, create a CSV file with the list of users (remember to add E-mail line for the first line of the file). Then import the CSV file and change the mailbox type:

Import-CSV C:\Reports\EXCH\user_to_shared_mailbox.csv | foreach {Get-Mailbox -Identity $_.Email | Where-Object {$_.RecipientTypeDetails -eq "UserMailbox"} | Set-Mailbox -Type Shared}

Do not delete the user account in AD just because the public mailbox is associated with it.

If you want to convert a shared mailbox back to a user’s mailbox, run this command:

Set-Mailbox a.shepherd -Type Regular

If you have a hybrid Exchange configuration, you’ll need to migrate your mailboxes to on-premises Exchange, convert them, and then bring them back to Microsoft 365.

Converting a User Mailbox to a Shared Mailbox in Exchange Online (Microsoft 365)

In Exchange Online, you can convert a user mailbox to a shared mailbox by using the Exchange Admin Center (EAC) or PowerShell.

1. 1. Sign up Sign In Exchange Admin Center;
   2. go for The recipient , mailbox,
   3. Select the user whose mailbox you want to convert;
   4. navigate to Other tab and click convert to shared mailbox,
   5. Confirm mailbox conversion;
   6. If the mailbox size is less than 50 GB, you can remove its Microsoft 365/AzureAD license.
      The size of a shared mailbox without a license cannot exceed 50 GB. Check current Exchange mailbox size and clear its contents if it exceeds 50 GB.

Additionally, you can convert user mailboxes to shared mailboxes by using PowerShell. Connect to your Microsoft 365 tenant using the EXO PowerShell module:

Connect-ExchangeOnline

To change the mailbox type shared mailboxRun the command below:

Set-Mailbox –Identity a.shepherd -Type Shared

You can convert it back the same way:

Set-Mailbox –Identity a.shepherd -Type Regular

Assign licenses to mailboxes within 30 days.