The Domino router uses Notes items such as SendTo and CopyTo (as well as some variants such as $INETSendTo) to determine where things go, whether from server to server or out to the Internet. I guess that could be considered "old-fashioned", but fundamentally, the MIME parts are just content to be moved around. The router will use the Notes items to look up or calculate the correct MIME information as mail moves out of the system. If you set that in the MIME, you are taking over the job of looking up addresses and so forth. We do both sorts in our CoexLinks Fidelity product. but we also handle all the name lookups and so forth when necessary.