Create a shared mailbox in Exchange or Office 365

Last reviewed on September 22, 2012

You can create a shared mailbox in Office 365, for addresses shared among users, such as for Sales, Info, or Billing. Assign Send As permissions to users and they can send mail or reply to messages using that address. The mailbox will be added to their profile automatically. Note that these mailboxes do not require a license, so there is no extra charge for them.

You'll need to use PowerShell to create shared mailboxes, you cannot use the console.

Office 365

Enter the following commands in PowerShell to log into Office 365

$LiveCred = Get-Credential

$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://ps.outlook.com/powershell/ -Credential $LiveCred -Authentication Basic -AllowRedirection

Import-PSSession $Session

If you receive this error message: Import-PSSession : Files cannot be loaded because the running of scripts is disabled on this system. Please provide a valid certificate with which to sign the files.

Use this code then rerun the Import-PSSession $Session from above. If you did not receive the error, you are ready to create the shared mailbox.

Set-ExecutionPolicy Unrestricted

Create the Shared Mailbox:

New-Mailbox -Name "Account Manager" -Alias accounts -Shared

Set a lower quota:

Set-Mailbox accounts -ProhibitSendReceiveQuota 5GB -ProhibitSendQuota 4.75GB -IssueWarningQuota 4.5GB

Assign FullAccess right to either a user or a security group. If you are giving full access to a group of people, use a security group because it is much easier to manage. Use the user alias only when a very limited number of people will need rights. When a user has full rights directly, the mailbox will show up in the profile automatically as a second mailbox; group members will need to add the mailbox to their profile in Account Settings, double click on account, More Settings.

Add-MailboxPermission "Account Manager" -User AcctMrgDG -AccessRights FullAccess

Give the same user or group Send as rights:

Add-RecipientPermission "Account Manager" -Trustee AcctMrgDG -AccessRights SendAs

When you are finished, you should end the session before closing the powershell window, otherwise your credentials are "live" for 15 minutes after the window is closed.

Remove-PSSession $Session

To check the configuration, use these cmdlets:

Get-Mailbox alias

Get-RecipientPermission alias

GUI Tool from Office 365

The Office 365 product team released a GUI-based tool to make it easier to create and configure shared mailboxes. You need to create the create a security group then run the tool to create a shared mailbox and assign FullAccess and SendAs permissions to your security group. Download the tool from Create Shared Mailboxes with GUI-based Tool. Note that this tool only works with security groups, not user accounts. If you want to create a shared mailbox and assign it to a user, you need to use the PowerShell commands above.

Written by

Diane Poremsky
A Microsoft Outlook Most Valuable Professional (MVP) since 1999 and involved in IT support since 1985, Diane is the author of several books and video training CDs and online training classes for Microsoft Outlook. You can find her helping people online in Outlook Forums as well as in the Microsoft Answers and TechNet forums.