How to validate non-english (UTF-8) encoded email address in Javascript and PHP?

Question

Part of a website I am currently working on contains registration process where users have to provide their email address. Just recently I became aware that non-ascii based

Answer 1

As offered by Mario, playing around a bit, I came up with the following regex to validate non-standard email address:

^([\p{L}\_\.\-\d]+)@([\p{L}\-\.\d]+)((\.(\p{L}){2,63})+)$

It would validate any proper email address with all kind of Unicode letters, with TLD limitations from 2 to 63 characters.

Please check it and let me know if there are any flaws.

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