Hi there, I'm really puzzled by this problem, maybe you can help? I'm trying to send on behalf of another user within exchange. I have set myself up as a delegate for the users mailbox in Outlook aswell as granting myself 'send on behalf of' permisions in AD. My problem is when I create a new mail and select his mail box and send the email. The email is received without the heading 'sent on behalf of'. What am i doing wrong?

Hi Davie, Do you have Send-As permission on that users mailbox? If yes then remove it and check. Use either of method, either outlook delegation or send on behalf of in AD. Sending 'As' http://www.msexchange.org/tutorials/Sending-As.html

Hi Davie, If Amits suggestions still not work, please remove your delegation permission on users mailbox, re-add On behalf of permission on ADUC, the article below will help How to grant Send On Behalf Of permission

Hi, Davie, I assume your question has been answered, and I'd like to change the status to "Marked as answer", please feel free to post here if you have any update