Send on Behalf vs Send As Permissions

Both Send on Behalf and Send As are similar permissions, however, there is one difference between these two permissions. Send on Behalf will allow a user to send as another user, when an email message arrives, the email message that is being sent on behalf of the mailbox owner is displayed. For example, Morgan sends an email message on behalf of Kevin. On other hand, the Send As permission allow a user to send mail as another person, in this case, the recipient should have no idea about who sent the message. Send As permission can be more useful where you are send message as a mail-enabled distribution group (ex: [email protected]).

Consider the scenario:

– Admin1 has Send on Behalf permision on User1
– Admin2 has Send As permision on User2

If the “Admin1” send message as “User1” with Send on Behalf permission, the recipient receive the message with the From field “Admin1 on behalf of User1“.

If the “Admin2” send message as “User2” with Send As permission, the recipient receive the message with the From field only “User1“, the recipient should have no idea about “Admin2“.

Grant Send on Behalf Permission

We can grant send on behalf permissions for a mailbox user using the powershell cmdlet Set-Mailbox with the parameter GrantSendOnBehalfTo.

The following command grants “Morgan” send on behalf permission to Kevin’s mailbox.

Set-Mailbox "Kevin" -GrantSendOnBehalfTo @{add="Morgan"}

Grant Send As Permission

We can grant Send As permission for a mailbox user using the Add-ADPermission powershell cmdlet. To perform this task, your account need to be added in the server roles Organization Management and Recipient Management.

The following command grants “Morgan” send as permission to Kevin’s mailbox.

Add-ADPermission -Identity "Kevin" -User "Morgan" -Extendedrights "Send As"