Administrators often need to give one or more users access to several shared mailboxes. For example, a new sales representative may require access to sales-info@, sales-support@, and sales-deals@ from their first day.
Assigning these permissions individually can quickly become repetitive, particularly when several users or mailboxes are involved. A suitable bulk-management approach can reduce manual work, maintain consistent permissions, and minimize configuration errors. This guide explains how to add multiple shared mailboxes to users in Microsoft 365 efficiently.
Shared Mailbox Permissions in Exchange Online
Before assigning access, it is important to understand the three main permission types available for shared mailboxes:
- Full Access (Read and manage): Allows a user to open the mailbox and manage its contents. It does not allow the user to send messages from the mailbox.
- Send As: Allows a user to send messages that appear to come directly from the shared mailbox.
- Send on Behalf: Allows a user to send messages showing that they sent them on behalf of the shared mailbox.
Users commonly require both Full Access and Send As permissions to work with a shared mailbox effectively.
Method 1: Delegate Exchange Online Mailboxes Using Microsoft 365 Admin Center
The standard Microsoft 365 admin center does not natively support assigning a user to multiple shared mailboxes in a single section. You must update each shared mailbox individually.
- Sign in to the Microsoft 365 admin center using your admin credentials.
- In the left navigation menu, go to Teams & groups > Shared mailboxes.
- Click on the first shared mailbox you want to delegate.
- In the properties pane that opens on the right, find the Manage mailbox permissions.
- Click on Read and manage permissions or Send as permissions or Send on behalf of permissions, depending on what the user needs.
- Repeat the process for every shared mailbox the users need to access.
This method works well when you only need to configure a few mailboxes. However, it becomes repetitive and time-consuming when several shared mailboxes are involved.
Method 2: Bulk Assigning Multiple Shared Mailboxes Using PowerShell
For larger operations, Microsoft administrators rely on PowerShell. Using the ExchangeOnlineManagement module, you can loop through a list of mailboxes and permissions to a user in one execution.
First, open your PowerShell console and connect to your tenant.
Connect-ExchangeOnline -UserPrincipalName "admin@yourdomain.com"Define the user and shared mailboxes, and then grant Full Access and Send As permissions.
# Define the user who requires access
$User = "user@yourdomain.com"
# Define the shared mailboxes
$Mailboxes = @(
"sharedmailbox1@yourdomain.com"
"sharedmailbox2@yourdomain.com"
"sharedmailbox3@yourdomain.com"
)
# Grant Full Access and Send As permissions
foreach ($Mailbox in $Mailboxes) {
Add-MailboxPermission `
-Identity $Mailbox `
-User $User `
-AccessRights FullAccess `
-InheritanceType All `
-Confirm:$false
Add-RecipientPermission `
-Identity $Mailbox `
-Trustee $User `
-AccessRights SendAs `
-Confirm:$false
}Replace admin@yourdomain.com with your admin email, user@yourdomain.com with the user getting access, and the sharedmailbox lines with your actual shared mailbox addresses.
Method 3: Bulk Add Shared Mailbox Permissions Using EasyEntra
EasyEntra offers a middle ground by bringing bulk-editing capabilities to a graphical user interface. If you can group your target shared mailboxes into a single view, you can change their permissions simultaneously without writing scripts.
To add multiple shared mailboxes to a user in EasyEntra, do the following steps.
- Navigate to Entra ID > Users.
- Filter your view to display the target shared mailboxes. You can use an LDAP filter in the search bar to narrow them down by common attributes.
- Example filter: (&(name=*shared*)(department=sales)) queries any object containing “shared” in the name and assigned to the “sales” department.
- Once the matching shared mailboxes appear in the view, select the objects you want to modify (hold Ctrl to select specific ones, or Ctrl + A for all).
- Right-click the highlighted selection and choose Properties.
- Go to the mailbox permissions tab. EasyEntra will display the permissions of the first object in your selected list.
- Add or remove the delegate user under the desired permission type (e.g., SendAs, SendOnBehalf, or FullAccess) and click save.
EasyEntra uses delta changes when bulk-editing mailbox permissions. Only the selected addition or removal is applied across the chosen mailboxes. All other existing delegate permissions remain unchanged.
The following demonstrations show how mailbox delegation works in EasyEntra:
