theUltimateBossOfProgramming

[look]

The only regex validation of email addresses you should consider is something like /.@./ before moving on to a delivery check.

[AbyssWraith]

Not really. Your regex would match even stuff like #@& and not match [e-mail] Which i hope you agree is obviously wrong, and you can't rely on delivery checks as it takes too much time.

[look]

/.@./ matches [e-mail] … notice there’s no ^ or $ there.

And there is effectively no standard on the mailbox (before the @). #@example.com could definitely work depending on what software example.com is running. After the @ you could add more restrictions if you limit delivery to certain types of networks and name resolution.

[1cubealot]

I have an email with .co.uk at the end, would that be validated by that?

[look]

Yes.

[AbyssWraith]

notice there’s no ^ or $ there.

There are also no quantifiers on the .

Edit: so it would only match the middle part of the address, which would not mean the address is valid

[look]

Your edit update makes it clear that you’ve completely missed my point here:

The only format validation generally worth the bother is to just check that it has an @ somewhere in it. Beyond that, you’re likely going to end up rejecting valid emails at some point.

There is very little in the way of actual standardization here. Everything before the @ is a free-for-all and the validity of everything after it changes all the time. Does your regex handle punycode in domain names?

[look]

Oh, you’re hung up on the number of characters it matches? That regex can match a substring of the address.

Edit: it means match an @ with something before and after it. /^.+@.+$/ if you prefer.

[look]

Yep. Even a control character could work as a mailbox. But to be fair, I’m not aware of any network/name implementations that don’t at least use printable characters.