On Sun, Dec 29, 2013 at 10:09:12PM -0500, Wietse Venema wrote: > Indeed. SMTPUTF8 support involves more than the 1% that says "I can > do SMTPUTF8" in the EHLO handshake. There is a whole list of RFCs > that need to be supported first.
I think the RFCs in question are a mistake. A far simpler and cleaner design would have been to extend Punycode to the local part of the address. For some reason the IETF working group did not choose the approach with the simplest migration path. There are other IETF RFCs that never get much adoption, I hope and expect that these will be among them. -- Viktor.