You might be able to use an SMTP event sink vbscript to append this. But, can you not simply use the (unique) message-id header that Exchange appends to emails? ________________________________ From: exchangelist-bounce@xxxxxxxxxxxxx [mailto:exchangelist-bounce@xxxxxxxxxxxxx] On Behalf Of Ahmad Sent: 29 January 2008 09:14 To: exchangelist@xxxxxxxxxxxxx Subject: [ExchangeList] Outgoing mails Auto Reference Number Dear All- We are using Exchange 2003 on windows 2003 server ..we need to add auto genarated numbers in every outgoing mails of all the users for tracking purpose .. is there any special software for this ..or it is possible from Exchange sever itself .. please help me out .. -- Regards, Shamshad Ahmad http://shamshad78.blogspot.com ______________________________________________________________________ The information contained in or attached to this email is intended only for the use of the individual or entity to which it is addressed. If you are not the intended recipient, or a person responsible for delivering it to the intended recipient, you are not authorised to and must not disclose, copy, distribute, or retain this message or any part of it. It may contain information which is confidential and/or covered by legal professional or other privilege (or other rules or laws with similar effect in jurisdictions outside England and Wales). The views expressed in this email are not necessarily the views of Centrica plc, and the company, its directors, officers or employees make no representation or accept any liability for its accuracy or completeness unless expressly stated to the contrary. ______________________________________________________________________