> Browsers automatically provide validation to ensure that only text that matches the standard format for Internet email addresses is entered into the input box. Browsers use an algorithm equivalent to the following regular expression:

> /^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/;

Which doesn't even allow all valid email addresses :|

No support for quoted local parts. No support for punycode domains. Disappointing.

Use <input type="text" inputmode="email"> instead to just get the email-optimized keyboard on phones without the misguided validation.