Ask HN: When will MTA/MUAs accept IDN emails?
Year after year, I expect MTAs and MUAs to properly implement punycode handling in email addresses, but a vast majority of them are still broken (Thunderbird, Exchange, Outlook, etc) even on the latest versions, as they complain, fail, or even crash. I'm wondering why there aren't anyone focusing on this issue, as IDN is becoming commonplace. It seems only Gmail is able to properly handle those emails, as well as my provider Gandi.
Here are some test email addresses to play with : - éé@éé.net (xn--9caa@xn--9caa.net) - éé.net@éé.net (xn--9caa.net@xn--9caa.net) According to RFCs, those emails are legit. (more here: https://en.wikipedia.org/wiki/International_email).
I'd be interested in any feedback on success rate while sending a message, and obviously an impulse to MTA/MUA developers so they can handle this properly.
As an example, Thunderbird 45.8.0 (latest version) accepts sending to éé@éé.net, but generates an error when sending to éé.net@éé.net, complaining it doesn't allows non-ascii characters in the local part of the email address... That's clearly a bug (since the former address which also contains non-ascii is accepted).
Many thanks. Bruno