Not sure if this is applicable to your scenario, but if you’re validating user input, you can use type="email" and make this the browser’s problem.

According to the docs, browsers use an algorithm equivalent to this regex for email input types:

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

So that could be a reasonably good baseline generally especially if you want to use those inputs at some point. However this does only check that the email address is of a valid format rather than necessarily meaning it is actually a valid email address, for that you likely need to go down the route of sending a validation link to the email address. It is also worth keeping in mind that if you are only doing this check in the client side then it will still be possible for someone to send messed up data directly to the server.

Can you try below code, I am sure you can get what you are looking for.

function validateEmail(email) {
    // Regular expression to validate email format
    var regex = /^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/;

    if (regex.test(email)) {
        return true;
    } else {
        return false;
    }
}

var userEmail = "user@example.com";
var isValid = validateEmail(userEmail);

if (isValid) {
    console.log("Email is valid.");
} else {
    console.log("Email is not valid.");
}

Thanks