Paul Borokhov writes:
Isn’t this just an implementation detail? Why should (average) users be exposed to it?
It's an entrenched implementation detail. It's entrenched in both software and average users. The secretary at my children's school is a nice example. She has an Excel sheet with all the parents' email addresses. She expects that she can update that sheet with addresses she sees in parents' mail and also that the addresses are readable and understandable over the phone. Lufthansa's customer service expects the same thing. Both that the addresses they see in my email are readable to me over the phone, and that an address I read to them over the phone is usable to send me mail. And so on and so forth. Jiankang wrote that some readers may prefer punycode. But that doesn't matter to senders, because some other readers reject punycode. Some customer service representative would see Don's new email address (from the attached screenshot) and say "Mr, Hollander, I'm afraid there appears to be an arror with your email address. Is tee oh aye at ex enn hyphen hyphen enn que pee you kay aye pee you kay aye dot enn zed correct? Do you perhaps have another address we can use?" Authors of software must assume that sending a punycoded address risks being rejected by some recipients. Arnt
