Simple Email Validations

email-check.js

/**
 * Simple email validation
 * ensures at least one `@` sign, at least one char in local part,
 * at least one `.` in domain part and is at least one char long
 */
isEmail: function (em) {
  em = em || '';
  var indx = em.lastIndexOf('@');
  return indx > 0 && (em.lastIndexOf('.') > indx) && (em.length - indx > 1);
}

module.exports = isEmail;

This might work better, and closer to HTML5 email validation:

var pattern = /^[a-zA-Z0-9._\-]+@[a-zA-Z0-9.\-]+\.[a-zA-Z]{2,4}$/g;
return pattern.test(email);

Source: https://github.com/dsheiko/HTML5-Form-Shim/blob/master/js/source/Input/Email.js

Yes, your regex solution will work, and I would prefer applying it in forms to validate email addresses. I have written the simple validation routine just to avoid the most blatant ones.