This is another blog post about Microsoft 365 and Exchange Online. This time I will dedicate myself to a feature that is Outlook and Exchange related. What I am talking about is granting mailbox Send and SendAs permissions. Do you have an overview of what is going on in your environment and foremost who has granted send or sendas permissons to other users? If not, read on.

Connect to Exchange Online

First of all we need to connect to Exchange Online. Hit the keys and enter the following lines to connect to your tenant.

$Session = New-PSSession -ConfigurationName Microsoft.Exchange `
-ConnectionUri https://outlook.office365.com/powershell-liveid/ `
-Credential (Get-Credential) -Authentication Basic -AllowRedirection

Import-PSSession $Session -DisableNameChecking

How do you know that worked? You should see a screen that shows exported commands.

Retrieve a list of all Send and SendAs Permissions

Type the following code to get a list of all user mailboxes that have send or sendAs rights configured:

Get-Mailbox -ResultSize Unlimited |
Get-RecipientPermission |
Where-Object {$_.Trustee -notlike "*self*"}

Nice one. As you can see, I have SendAs permissons on hubers mailbox 😉

Hope this was helpful!

See also

Microsoft 365: Show Mailboxes that have Auto-Reply enabled

Microsoft 365: Add User Accounts and Mailboxes with PowerShell