Give a User 'SendAs' permssions to a Mail-Enabled AD Group in Exchange Online

Really specific situation I know, but this took me an embarrassing amount of time to figure out.

Thankfully, its pretty simple. Just use the 'RecipientPermission' cmdlets:

Add-RecipientPermission -Identity GROUP -Trustee USERNAME -AccessRights SendAs

Where GROUP is the 'samAccountName' or 'Primary Email' of the group you want to allow the user to send as and USERNAME is the 'samAccountName' of the user.

You can also use the following to see who already has 'Send As' permissions for the group

Get-RecipientPermission -Identity GROUP

Example: