I have a user who is doing his job from his home office mainly. He connects with Outlook 2007 to our Exchange 2007 server using HTTP. It works fine, but the problem is, when he is trying to reply mails using a customer service email address instead of his own. Each time he sends a message with customer address in the "From" line, he received an error message stating "You are not allowed...to send on behalf of another sender without permission to do so". The message comes from our Exchange though the user is granted both, full access to the mailbox and "Send As" permission.

Is there any general limitation in this functionality when using Outlook over HTTP? Could this be the reason?

Thanks a lot

Eduard

Hi,

Let the user try to do the same on a PC in office instead of his home, does this issue exist? If the user doesn't have this issue when working on another PC, we can say the permission has actually been granted correctly. We may consider the issue is related to something on the home PC.

We can try to clear the Outlook related credentials from the Credential Manager on the home PC. Take Windows 8.1 for example:

Control Panel -> User Accounts -> Credential Manager -> Windows Credentials. Check if there is any credential of Outlook, remove it, then open Outlook to check the result again.

Regards,

Melon Chen
TechNet Community Support

Hello Melon,

This particular user can send mails with alternative sender's email address when using OWA so I believe the permissions are set correctly. I will ask him to try it with the Credential Manager.

Thank you.