On 24/04/15 21:15, John C Klensin wrote: > Just don't try to encode local parts. Really. You will
> hurt the sites and systems that support non-ASCII addresses and
> headers all the way to the client desktop and won't really help
> those who don't.
Are you speaking to pure MTAs here, or also MSAs? MUAs?
> Exim, as an MTA