Office 365 Full Access Mailbox Permissions

If you administer an Office365/Exchange Online organization, you might have noticed you cannot modify Full Access/Send As permissions from the web console. You need to change these permissions through PowerShell; here are the required steps:

The first time you do this, make sure the following steps have been completed:

  1. Right click and run PowerShell as Administrator (Start -> Programs -> Accessories -> Windows PowerShell -> Windows PowerShell) on your local PC

  2. Verify you are running PowerShell 2.0 - Enter $PSVersionTable in the prompt and hit enter

  3. Allow execution of scripts by entering the following command: Set-ExecutionPolicy Unrestricted

Once those two steps have been completed, you can start from here:

  1. Enter the following command and input your Exchange admin credentials when prompted:

$LiveCred = Get-Credential

  1. Once completed, enter this command next:

$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri -Credential $LiveCred -Authentication Basic -AllowRedirection

  1. Next, enter the following command to import server-side commands:

Import-PSSession $Session

  1. To allow user BossOne to have full access to user WorkerOne, enter the following command:

Add-MailboxPermission -Identity "WorkerOne" -User BossOne -AccessRights FullAccess

  1. Verify your work with:

Get-MailboxPermission Username

  1. Once completed, discconect from the remote session with:

Remove-PSSession $Session

If you also need to add "SendAs" permissions, the command is:

Add-RecipientPermission "mailboxuser" -AccessRights SendAs -Trustee "user"

Verification command is:

Get-RecipientPermission Username