Ajax Email validation

email-validation.js

var $contactForm = $('#contactForm'),
    $submitButton = $('#submitForm'),
    $message = $('.js-error-messages'),
    $honeypot = $('.js-honey'),
    $emailField = $('.js-email-field');

var resetButton = function(timeout) {
  setTimeout(function() {
    $submitButton.text('Send').prop('disabled', false);
  }, timeout);
};

var honeypotEmpty = function() {
  return $honeypot.val() === '';
};

var hasValue = function(index, element) {
  return $(element).val() !== '';
};

var hasFieldValues = function() {
  var numberOfFields = $('.form__field.required').length;
  return $formFields.filter(hasValue).length === numberOfFields;
};

var hasValidEmail = function() {
  var regEx = /^([0-9a-zA-Z]([-.\w]*[0-9a-zA-Z])*@([0-9a-zA-Z][-\w]*[0-9a-zA-Z]\.)+[a-zA-Z]{2,9})$/;
  return regEx.test($emailField.val());
};

var validateForm = function() {
  if (!honeypotEmpty()) {
    $message.text('You are not a human');
    return;
  }
  if (!hasFieldValues()) {
    $message.text('Please fill in all fields');
    return;
  }
  if (!hasValidEmail()) {
    $message.text('Your email address is not valid');
  }
};

var formValid = function() {
  return (honeypotEmpty() && hasFieldValues() && hasValidEmail());
};

var postToMailer = function(e) {
  e.preventDefault();
  $message.empty();
  validateForm();
  if (!formValid()) { return; }
  $submitButton.text('Sending...').prop('disabled', true);
  $.ajax({
    url: this.action,
    method: this.method,
    data: $(this).serialize(),
    success: function(data) {
      $submitButton.text('Sent');
      $message.text('Success:' + data);
      resetButton(5000);
    },
    error: function(jqXHR, textStatus) {
      $message.text('Error: ' + textStatus);
      resetButton(7000);
    }
  });
};


$contactForm.on('submit', postToMailer);