The Exchange admin centre covers the basics but PowerShell is much faster when you're working with multiple mailboxes, need to script recurring tasks, or want to make changes that the GUI doesn't expose. This guide covers the most common shared mailbox and distribution group tasks you'll run into day-to-day.
Connect to Exchange Online
PowerShell
# Install the module if you haven't already
Install-Module -Name ExchangeOnlineManagement -Force
# Connect - this opens a browser auth prompt
Connect-ExchangeOnline -UserPrincipalName admin@yourdomain.comShared Mailboxes
📬 Shared MailboxesCreate a new shared mailbox
PowerShell
New-Mailbox -Shared -Name "IT Support" -DisplayName "IT Support" -Alias itsupport -PrimarySmtpAddress "itsupport@yourdomain.com"Give a user Full Access to a shared mailbox
PowerShell
Add-MailboxPermission -Identity "itsupport@yourdomain.com" -User "jane@yourdomain.com" -AccessRights FullAccess -AutoMapping $true
# AutoMapping:$true makes the mailbox appear automatically in OutlookGive Send As permission
PowerShell
Add-RecipientPermission -Identity "itsupport@yourdomain.com" -Trustee "jane@yourdomain.com" -AccessRights SendAs -Confirm:$falseConvert a regular mailbox to shared
This is useful when an employee leaves and you want to keep the mailbox accessible to their team without paying for an ongoing licence.
PowerShell
# Convert to shared first
Set-Mailbox -Identity "leaveruser@yourdomain.com" -Type Shared
# Then remove the licence from the account in Entra ID / M365 admin
# Shared mailboxes under 50GB don't need a licenceRemove the licence after converting
Once a mailbox is converted to shared and is under 50GB, it doesn't need a paid licence. Remove the M365 licence from the user account in the admin centre after converting to avoid the ongoing cost. The mailbox stays accessible to anyone with Full Access permission.
Hide a shared mailbox from the Global Address List
PowerShell
Set-Mailbox -Identity "itsupport@yourdomain.com" -HiddenFromAddressListsEnabled $trueAdd a secondary email address (alias)
PowerShell
Set-Mailbox -Identity "itsupport@yourdomain.com" -EmailAddresses @{Add="it@yourdomain.com"}Distribution Groups
📋 Distribution GroupsCreate a distribution group
PowerShell
New-DistributionGroup -Name "All Staff" -Alias allstaff -PrimarySmtpAddress "allstaff@yourdomain.com" -MemberJoinRestriction ClosedAdd members to a distribution group
PowerShell
Add-DistributionGroupMember -Identity "All Staff" -Member "jane@yourdomain.com"
# Add multiple from a CSV
Import-Csv "C:\users.csv" | ForEach-Object {{
Add-DistributionGroupMember -Identity "All Staff" -Member $_.Email
}}List all members of a group
PowerShell
Get-DistributionGroupMember -Identity "All Staff" | Select-Object Name, PrimarySmtpAddressAllow external senders to email a distribution group
By default, distribution groups only accept mail from internal senders. To allow external email:
PowerShell
Set-DistributionGroup -Identity "All Staff" -RequireSenderAuthenticationEnabled $falseUse Microsoft 365 Groups instead for modern collaboration
Classic distribution groups only handle email. Microsoft 365 Groups (also known as Unified Groups) include a shared mailbox, SharePoint site, Teams channel, and Planner board. For new groups where collaboration matters, M365 Groups are the better choice. You can create them with New-UnifiedGroup in PowerShell.