blacklist chars of the localpart or userpart of internatinalize emails address

[AkaeyesWanabe]

Hello ! Could i know or get the list of blacklist characters of the userpart or localpart of internationalized email address.
Thank you.

[WikiRik]

It depends on the options used, but I think you want either of these two regular expressions;

validator.js/src/lib/isEmail.js

Lines 26 to 27 in cd4e7bf

	const emailUserUtf8Part = /^[a-z\d!#\$%&'\*\+\-\/=\?\^_`{\|}~\u00A1-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]+$/i;
	const quotedEmailUserUtf8 = /^([\s\x01-\x08\x0b\x0c\x0e-\x1f\x7f\x21\x23-\x5b\x5d-\x7e\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]|(\\[\x01-\x09\x0b\x0c\x0d-\x7f\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]))*$/i;

Check out the rest of the file as well to see what the validator does.

[AkaeyesWanabe]

Super thank you for explanations. it's great

[AkaeyesWanabe]

Now i want to know if some characters such as "?" ou "!" are valid characters and why?
you can see my hypothesis:
-it can be valid in non-internationalized emails and so will become valid in inernationalized email...
-they are only valid in internationalized emails.

Could i have somes documentations about invalid or valid characters in internationalized email addresses.
Really, Our team try to make a loca function to validate internationalized email addresses in PHP.

[WikiRik]

Could i have somes documentations about invalid or valid characters in internationalized email addresses.

That would be part of the RFCs relating to email itself and that exact knowledge is not something we as maintainers have. A start on how email addresses are built up and which RFCs are related to that can be given by reading the Wikipedia page; https://en.wikipedia.org/wiki/Email_address