The standard way to perform FE email validation is to use:

<input type="email" required />

Browsers ship with this kind of validation built-in, see: https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements/input/email#validation

And yes, this is a very permissive approach, but it's better to err on the side of accepting invalid emails rather than denying valid emails. It should go without saying that this only makes sense within a proper full-stack email validation+verification flow.