We're running Exch 2000 with muliple servers and Exch 2003 (different domain/Exch org) at another site with mainly outlook 2003 clients. Occasionally we have a problem where a user sends out a message and it's received with blank "To" and "From" fields. If the user checks with the recipient of their previous message or the one after this "bad" message there seems to be no problem and if they resendthe "bad"messagethe problem can't be reproduced. This seems to be completely random and happens every month or so. In the last one I monitored the header detail is shownin the ESMtracking tool. Also one of the recpients in the same message store as the sender received a message with a "winmail.dat" attachement, blank headers (except subject) and no message body, all the other recpients just had mising to/from headers.Does anyone have any idea what might be the cause?

Hi,To diagnose this issue, I suggest we install Archive Sink utility to capture message header for the message.You can use following knowledge base article to get more information about the functionality of Archive Sink and how to install it: http://support.microsoft.com/kb/871110Through that tool, we can get the message header in the stage of OnMessageSubmission and OnPostCategorize. Then confirm whether the message header was missing in local site or opposite site. Please send the files to me at v-allson@microsoft.comThanksAllen