Yeah, I think we'll have to treat email addresses as just another kind of untrustworthy input that needs to be escaped in various ways depending on the context.

Yeah, I think we'll have to treat email addresses as just another kind of untrustworthy input that needs to be escaped in various ways depending on the context. Punycode for storage and validation, back to UTF-8 for display, back to punycode when it goes in a mailto: link, etc. Ditto for URLs. The days of easy parsing are sadly forever gone.