I have noticed that one of the users if he sends me a Meeting Request and I send a Resposne after acceting it, the resposne goes to a different e-mail address than than the sender!!
The e-mail address sent to, was an old test ID created for some time but deleted.
so I get the delivery failure error:
Delivery has failed to these recipients or distribution lists:
The recipient's e-mail address was not found in the recipient's e-mail system. Microsoft Exchange will not try to redeliver this message for you. Please check the e-mail address and try resending this message, or provide the following diagnostic text to your system administrator
Secondly, if I edit the Reposne before sending it, I can see cleary it has the correct sender's address in the TO: field
and when I checked the user's ID (the sender) object on Active Directory, everything was fine with it..