That is the only correct answer. .+@.+ In human language: an email address consists of something, an @, and something. That's it. The name part can be an

That is the only correct answer. .+@.+ In human language: an email address consists of something, an @, and something. That's it. The name part can be anything; so don't validate it beyond having a character. We don't have one-character domains yet, but there is no reason to exclude them. It is already possible to arrange your own top-level domain if your pockets are deep enough (.google), so don't be surprised if some megacorp starts using a top-level domain without any subdomains. Don't validate the domain part beyond having a character.