What is Send As Permission?

Send As permission allows a user to send emails that appear to come from another mailbox. This is essential for shared mailboxes and delegated access scenarios.

Prerequisites

First, connect to Exchange Online PowerShell:

Connect-ExchangeOnline -UserPrincipalName admin@yourdomain.com

Grant Send As Permission

To grant Send As permission, use this command:

Add-RecipientPermission -Identity "sharedmailbox@domain.com" -Trustee "user@domain.com" -AccessRights SendAs -Confirm:$false

Verify Permissions

Check who has Send As permissions on a mailbox:

Get-RecipientPermission -Identity "sharedmailbox@domain.com" | Where-Object {$_.Trustee -ne "NT AUTHORITY\SELF"}

Remove Send As Permission

To revoke Send As permission:

Remove-RecipientPermission -Identity "sharedmailbox@domain.com" -Trustee "user@domain.com" -AccessRights SendAs -Confirm:$false

Common Use Cases

  • Shared department mailboxes (HR, Sales, Support)
  • Executive assistant sending on behalf of executives
  • Team collaboration scenarios