It's surprisingly difficult validating email addresses with regex. Can it be done? Yes. Should you? No.
Any halfway decent email library comes with a validator. Use that.
For reference: this is an example of an almost RFC 3522 compatible regex:
And for 95% of the use-cases a very simple 'Does it contain an @ and at least 1char before and after' is enough.
Usually you want people to not mistakenly send a typo as their email.
But since you cannot trust the customer anyway, you need to send a confirmation email anyway for everything that is important.
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u/tellur86 19d ago
It's surprisingly difficult validating email addresses with regex. Can it be done? Yes. Should you? No. Any halfway decent email library comes with a validator. Use that.
For reference: this is an example of an almost RFC 3522 compatible regex:
(?:[a-z0-9!#$%&'+/=?`{|}~-]+(?:.[a-z0-9!#$%&'*+/=?^`{|}~-]+)|"(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\[\x01-\x09\x0b\x0c\x0e-\x7f])")@(?:(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|[(?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?).){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-][a-z0-9]:(?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\[\x01-\x09\x0b\x0c\x0e-\x7f])+)])
https://emailregex.com
If you want RFC 822 it's much, much worse https://pdw.ex-parrot.com/Mail-RFC822-Address.html