Bulk create shared mailboxes with PowerShell

To add a shared mailbox in Exchange Online, you can do this manually in Microsoft 365 Admin Center. But it’s much faster to create multiple shared mailboxes and add users with access rights with a PowerShell script. In this article, you will learn how to bulk shared mailboxes in Exchange Online with PowerShell.

Connect to Exchange Online

Before creating shared mailboxes in the next step, you must install and connect to Exchange Online PowerShell. Start Windows PowerShell as administrator and run the below cmdlet.

Connect-ExchangeOnline

Create bulk shared mailboxes with PowerShell

For this step, you must create a single CSV file to use in PowerShell as a source file. Initially, we want to keep it simple and start to create bulk shared mailboxes only.

Create a single CSV file

First, we need to type the data into notepad and save it as a CSV file. In our example, it is saved as info.csv in C:\temp.

You should use the following format for the CSV file:

• Name: Unique email address of the shared mailbox
• DisplayName: Name of the shared mailbox

Check CSV file with Import-Csv cmdlet

Run Windows PowerShell as administrator. Make sure that PowerShell can read the file, run Import-Csv cmdlet.

Import-Csv "C:\temp\info.csv"

This is how it looks in our example.

PS C:\> Import-Csv "C:\temp\info.csv"

Name        DisplayName
----        -----------
Finance1    Finance Team
Marketing1  Marketing Team
HR1         HR Department
IT1         IT Department
Security1   Security Department
Management1 Management Team
Design1     Design Team
Sales1      Sales Team
Production1 Product Team
RD1         Research and Development

Run PowerShell script to create bulk shared mailboxes in Exchange Online

Use the below PowerShell script to create new shared mailboxes in Exchange Online.

# Import CSV file
$Datas = Import-Csv "C:\temp\info.csv"

# Get all recipients
$Recipients = Get-Recipient -ResultSize Unlimited | select Name

foreach ($Data in $Datas) {

    # Check if shared mailbox does not exist
    If (($Recipients | Where { $_.Name -eq $Data.Name }) -eq $Null) {

        # Create shared mailbox
        New-Mailbox -Name $Data.Name -DisplayName $Data.DisplayName -Shared
        Write-Host -f Green "Shared mailbox '$($Data.Name)' created successfully."
    }
    Else {
        Write-host -f Green "Shared Mailbox '$($Data.Name)' already exists."
    }
}

Check shared mailboxes in Microsoft 365 Admin Center

You managed to create bulk shared mailboxes in PowerShell. You can also check which shared mailboxes you created in the Microsoft 365 admin center.

The outcome will look like the picture below.

We have not assigned any users to these shared mailboxes. Look into the next step to add users with full access rights to each of these shared mailboxes.

Create bulk shared mailboxes with users access rights in PowerShell

For this step, you must create a CSV file with more data to use as a source file in PowerShell. We want to create shared mailboxes, import multiple users, and assign permission.

Create CSV to create bulk shared mailboxes with users

You need to type the following data format in the CSV file:

• Name: Unique email of the shared mailbox
• DisplayName: Name of the shared mailbox
• User: Active users
• AccessRights: FullAccess

In our example, we typed the data into notepad and named the file info.csv and placed it in C:\temp.

Check CSV file with Import-Csv cmdlet

Run Windows PowerShell as administrator. Make sure that PowerShell can read the file, run Import-Csv cmdlet.

Import-Csv "C:\temp\info.csv"

This is how it looks in our example.

PS C:\> Import-Csv "C:\temp\info.csv"

Name        DisplayName              User                                                AccessRights
----        -----------              ----                                                ------------
Finance1    Finance Team             Amanda Morgan;Stephen Hunter;Carol Baker            FullAccess
Marketing1  Marketing Team           Craig Hansen;Edward Jones                           FullAccess
HR1         HR Department            Edward Wilson;Emma Arnold;Nick Carlson;Lisa Philips FullAccess
IT1         IT Department            Piers Bower;Lisa Davies;Anna Welch;John Hamod       FullAccess
Security1   Security Department      Edward Wilson;Jonathan Fisher                       FullAccess
Management1 Management Team          Neil Graham;Sarah Coleman;Viola Simon               FullAccess
Design1     Design Team              Wallace Zheng;Abigail Hodges;Emma Arnold            FullAccess
Sales1      Sales Team               Edward Lincoln;Amanda Morgan;Stephen Hunter         FullAccess
Production1 Product Team             Kylie Davidson;Mary Walsh                           FullAccess
RD1         Research and Development Max Gibson;Curt Berry;Owen Simpson                  FullAccess

Run PowerShell script to bulk create shared mailboxes in Exchange Online with users access rights

Run the below PowerShell script to create shared mailboxes in Exchange Online. You can create multiple shared mailboxes, add existing users and assign permission simultaneously.

The PowerShell output lets you know if the shared mailbox already exists. If you have an incorrect user in your CSV file, the output will inform you that the user was not found. It will also not add an existing user twice to the same shared mailbox. You will get a warning that the user access rights are already present on this shared mailbox.

# Import CSV file
$Datas = Import-Csv "C:\temp\info.csv"

# Get all recipients
$Recipients = Get-Recipient -ResultSize Unlimited | select Name

foreach ($Data in $Datas) {

    # Check if shared mailbox does not exist
    If (($Recipients | Where { $_.Name -eq $Data.Name }) -eq $Null) {

        # Create shared mailbox
        New-Mailbox -Name $Data.Name -DisplayName $Data.DisplayName -Shared
        Write-Host -f Green "Shared mailbox '$($Data.Name)' created successfully."
    }
    Else {
        Write-Host -f Green "Shared Mailbox '$($Data.Name)' already exists."
    }
    # Assign permissions on shared mailbox
    $Users = $Data.User -split ";"
    foreach ($User in $Users) {
        Add-MailboxPermission -Identity $Data.Name -User $User.Trim() -AccessRights $Data.AccessRights
    }
}

Check shared mailboxes with its users and permission in Microsoft 365 Admin Center

You will see the shared mailboxes in the Microsoft 365 admin center. If you click on each shared mailbox, you will see how many users are assigned and their permission.

If you click Read and manage permissions, you will see which users are assigned to the shared mailbox.

Did you find it easy to use a PowerShell script to create bulk shared mailboxes with users and grant them access rights?

Read more: Enable reply all storm protection in Exchange Online »

Conclusion

You learned how to create bulk shared mailboxes with a PowerShell script and a CSV file. It is the fastest way to import over a thousand users and assign their access rights to multiple shared mailboxes. Our last PowerShell script allows you to create bulk shared mailboxes, add multiple users to each shared mailbox and grant them access rights.

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