Tach,

Insgesamt sieht es so aus, als hätte man es sich einfach machen wollen.

ah, sehe schon, die WhatWG-Spec ist Aussagekräftiger:

"User agents may transform the value for display and editing (e.g. converting punycode in the value to IDN in the display and vice versa)." und "This requirement is a willful violation  of RFC 5322, which defines a syntax for e-mail addresses that is simultaneously too strict (before the "@" character), too vague (after the "@" character), and too lax (allowing comments, white space characters, and quoted strings in manners unfamiliar to most users) to be of practical use here."

mfg
Woodfighter