Implementing the authoritative version is a waste since you'll also need to keep an up-to-date list of TLDs, and more importantly, you might have a typo in the

Implementing the authoritative version is a waste since you'll also need to keep an up-to-date list of TLDs, and more importantly, you might have a typo in the input that gives a valid-but-incorrect email. After doing your simple regex, the best move is to just send a verification email and wait for the user to click the link, if you really need to be sure.