Sometimes you need to grant a user access to another Office 365 mailbox. This is standard practice for shared mailboxes and Room and Equipment mailboxes.
You may also need to delegate access to regular user mailboxes e.g. in case a secretary should be able to manage the mailbox of a manager.
In Office 365 there are three types of delegation on a regular user mailbox:
- Send As
- Send on Behalf
- Full Access
You’ll also learn how to do it via the Exchange Admin Center and via the standard AD Users & Computers management console.
Mailbox Delegation Using PowerShell
- $UserCredential = Get-Credential
- $Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $UserCredential -Authentication Basic -AllowRedirection
- Import-PSSession $Session -DisableNameChecking
- Add-MailboxPermission firstname.lastname@example.org -User email@example.com -AccessRights FullAccess
- Remove-PSSession $Session
- Start by establishing a connection with Exchange Online (line 1 – 3).
- Delegate access to the mailbox using the Add-MailboxPermission command (line 4).
- End your Exchange Online session when done (line 5). If you don’t explicitly close the session you risk depleting the number of available sessions.
To review your change use Get-MailboxPermission. The output may look similar to this:
Notice that there are a lot of default permissions.
You can clean up your output by using some filtering:
Delegating Mailbox Access Using Exchange Admin Center
You can also delegate mailbox access using the Exchange Admin Center. Follow the below steps to delegate permissions to a mailbox.
Open up the Exchange Admin Center using your admin account and locate the mailbox you want to delegate access to:
Open up mailbox properties and select Mailbox Delegation:
Select what type of access you want to delegate and add the delegatees.
Mailbox Delegation Using Active Directory Users & Computers
The final option is to perform the mailbox delegation using the Active Directory Users & Computers management console. You need to have the Easy365Manager snapin installed to follow this procedure. You can download a free fully functional trial here.
Open up user properties and go to the Mailbox tab. Click on Mailbox Delegation. Then add the the delegatees to the selected type of delegation: