Email Addresses are Special

So you want to build an email address validator?

Here is some information that can be helpful.

DO NOT USE REGEX

Regular Expressions are powerful however, it is truly the wrong tool for the job.

This is Perl's Regular Expression For Email Validation

So as you can see to get a fully complete email validator is a messy process in Regex and I am assuming that the performance is not that great

Emails are very permissive

For Example, These Are Some of my favorite valid emails

// It is in between quotes and the characters are escaped
"very.(),:;<>[]\".VERY.\"very@\ \"very\".unusual"@strange.example.com
// Yes this is valid. 
#!$%&'*+-/=?^_`{}|~@example.org
// Empty Space Between Quotes is allowed
" "@example.org

Implementing an Email Validator

If you decide to implement an email validator I recommend you read these resources first

RFC5322

Then have a ton of tests. This Repository Contains some JSON files with tests to help you test your email validator.

Feel free to add more tests.

Libraries that can do it for you

Find a Library to validate you because implementing it yourself is a mess

Rust

Feel free to PR more libraries

Thank You

kenorb for their invalid and valid emails on StackOverFlow.

wyatt-herkamp / email_addresses_are_special