We have a company that has recently changed from an outsourced e-mail provider to Exchange 2010. With the old e-mail provider, the system would send the ESMTP "RET=FULL" parameter, which would result in any NDR's getting a copy of the original message. Exchange doesn't send the RET= parameter at all, so the other systems (rightly) do not send the original message back. Is there any way of making Exchange send this parameter? (I have read the full thread at http://social.technet.microsoft.com/Forums/en-US/exchangesvrtransport/thread/55ce2fbe-3573-4661-a6bd-68b6d7fb4885 and, while full of good infomation, does not provide a solution.)

Hi KyleHutson, As I know, you should change the DSNConversionMode to DonotConvert, it will send the DSN as if it is sending the DSN in case of an Exchange 2003 server with the original message as the attachment. But this has a few drawbacks. Resource: DNSConversionMode and what is the difference between Delivered DSN and Relayed DSN http://blogs.technet.com/b/mohammad_qassim/archive/2011/04/10/dnsconversionmode-and-what-is-the-difference-between-delivered-dsn-and-relayed-dsn.aspx Frank Wang

After reading the article (and feel free to correct me if I'm wrong), it appears that this parameter deals with how Exchange generates DSNs. What I'm looking for is a way to generate the RET=FULL on every outbound message so that NDRs (I don't care about DSNs one way or the other) will have the original message attached.