In Mail.app, whenever I click on the curvy arrow to the left of a message in my inbox (meaning I replied to this message) a box comes up and says "Mail was unable to find your reply to the message [insert subject here]. You may have deleted the message. I most certainly did not delete the message. And when I open the "sent" folder, there it is, right where it should be. Is there some setting I have wrong? Everything else seems to work as it should. This is on an exchange account; with my gmail and mobileme it works fine. Thanks.