Dec. 13, 2017
1:47 a.m.
Question: Is there any reason that clients should *not* punycode *all* addresses when sending messages and convert them back to proper Unicode at display time?
Yes. For one thing, it would break mail to the majority of mail users who use ASCII mail clients. For another, the local parts of mail addresses are not always convertible to punycode, or if they are, there is a non-reversible canonicalization step so if you undo the punycode, you'll end up with the wrong local part and it won't be deliverable. R's. John PS: It probably isn't a big surprise that this isn't the first time this suggestion has come up.