Q:

Keep getting error when trying to submit this email form

I have made a form that emails the info entered in the fields but I am getting an error when filled out. 

Could not send mail!  Please check your PHP mail configuration. 

All the code seems good but I can't find the cause of the error.  The error shows once I try to submit the form (which is the error message meant to show on a send mail error).  Any help is greatly appreciated!! 
I should mention that there are 2 forms in the directory; Form "1", uses the "1" versions of the JS and PHP files, Form "2' uses the "2" version.  They do not share the JS and PHP files. 
<form id="email-form2" name="email-form2" method="POST" data-name="Insurance Form">
  Enter Name
  <input class="w-input text-field" id="name" type="text" placeholder="First name and last name" name="name" data-name="Name" required> Email
  <input class="w-input text-field" id="email" type="email" name="email" placeholder="Enter your email address" data-name="Email" required> Date of Birth
  <input class="w-input text-field" id="date" type="date" name="date" data-name="Date" required> Gender
  <input class="w-input text-field" id="gender" type="text" placeholder="Male or Female" name="gender" data-name="Gender" required> Member ID
  <input class="w-input text-field" id="member" type="text" placeholder="Member number" name="member" data-name="Member" required> Policy ID
  <input class="w-input text-field" id="policy" type="text" placeholder="Policy number" name="policy" data-name="Policy" required>
  <div class="div-spc">
    <button class="w-button button no-margin" type="submit">Submit Form</button>
  </div>
</form>

<? php
  if($_POST) 
  {
    $to_Email = "email@email.com"; //Replace with recipient email address

    //check if its an ajax request, exit if not
    if (! isset($_SERVER['HTTP_X_REQUESTED_WITH']) AND strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) ! = 'xmlhttprequest') 
    {   
      //exit script outputting json data
      $output = json_encode(array(
        'type'=> 'error',
        'text' => 'Request must come from Ajax'
      ));

      die($output);
  }

  //check $_POST vars are set, exit if any missing
  if (! isset($_POST["userName"]) || ! isset($_POST["userEmail"]) || ! isset($_POST["userDate"]) || ! isset($_POST["userGender"]) || ! isset($_POST["userMember"]) || ! isset($_POST["userPolicy"])) 
  {
    $output = json_encode(array('type'=>'error', 'text' => 'Input fields are empty!')); 
    die($output);
  }

  //additional php validation
  if (empty($_POST["userName"])) 
  {
    $output = json_encode(array('type'=>'error', 'text' => 'Name is too short or empty!')); 
    die($output);
  }

  if (! filter_var($_POST["userEmail"], FILTER_VALIDATE_EMAIL)) 
  {
    $output = json_encode(array('type'=>'error', 'text' => 'Please enter a valid email!')); 
    die($output);
  }

  if (empty($_POST["userMember"])) 
  {  
    $output = json_encode(array('type'=>'error', 'text' => 'Need Member ID number!')); 
    die($output);
  }

  if (empty($_POST["userGender"])) 
  {
    $output = json_encode(array('type'=>'error', 'text' => 'Please enter Male or Female!')); 
    die($output);
  }
  if (empty($_POST["userPolicy"])) 
  {
    $output = json_encode(array('type'=>'error', 'text' => 'Need Policy ID number!')); 
    die($output);
  }

  if (empty($_POST["userDate"])) 
  {
    $output = json_encode(array('type'=>'error', 'text' => 'Please fill out birth date!')); 
    die($output);
  }

  //proceed with PHP email. 
  $headers = 'From: '.$_POST["userEmail"].'' . " \r\n" . 
    'Reply-To: '.$_POST["userEmail"].'' . " \r\n" . 
    'X-Mailer: PHP/' .  phpversion();

  // send mail
  $sentMail = @mail($to_Email, $_POST["userName"], $_POST["userDate"], $_POST["userGender"], $_POST["userMember"], $_POST["userPolicy"], $headers);

  if (! $sentMail) 
  {
    $output = json_encode(array('type'=>'error', 'text' => 'Could not send mail!  Please check your PHP mail configuration.')); 
    die($output);
  } else {
    $output = json_encode(array('type'=>'message', 'text' => 'Hi '.$_POST["userName"] .'  Thank you for your email'));
    die($output);
  }
}
? >

$(document).on("ready", function() {
  $("#email-form2 [type='submit']").click(function(event) {
    event.preventDefault();
    //get input field values
    var user_name = $('input[name=name]').val()
    var user_email = $('input[name=email]').val()
    var user_date = $('input[name=date]').val()
    var user_gender = $('input[name=gender]').val()
    var user_member = $('input[name=member]').val()
    var user_policy = $('input[name=policy]').val()

    //data to be sent to server
    post_data = {
      'userName': user_name,
      'userEmail': user_email,
      'userGender': user_gender,
      'userMember': user_member,
      'userPolicy': user_policy,
      'userDate': user_date
    }

    //Ajax post data to server
    $.post('contact_me2.php', post_data, function(response) {
      //load json data from server and output message    
      if (response.type == 'error') {
        output = '<div class="error-message"><p class="from">' + response.text + '</p></div>'
      } else {
        output = '<div class="success-message"><p class="seuccses">' + response.text + '</p></div>'

        //reset values in all input fields
        $('#email-form2 input').val('')
      }
      $("#result").hide().html(output).slideDown()
    }, 'json')
  });

  //reset previously set border colors and hide all message on .keyup()
  $("#email-form2 input").keyup(function() {
    $("#result").slideUp()
  })
});

A:

If you take a look at the documentation for mail(), you'll see that the function accepts 5 parameters.  
Now, how many parameters are you sending it in your code? ( answer: 7).  Can you see how that might be a problem?  Also you're using @ at the start of mail() which will suppress any errors which might have been thrown as a result.  
Even if it doesn't error, you're sending it nonsensical data for everything after the $message parameter, and that's why it's not working.  I expect perhaps you really want to join all those various fields (username, gender, date, policy, etc) together in a single string, with some formatting such as spaces and newlines etc, so that it forms a coherent message body - rather than just firing them all at the mail() function and hoping it rearranges them into something readable (which, to be clear, it can't and won't). 
To give you a start, try this: 
$subject = "Some subject";
$message = $_POST["userName"]." " .$_POST["userDate"]." ".  $_POST["userGender"]." " .$_POST["userMember"]." " .$_POST["userPolicy"];
$sentMail = mail($to_Email, $subject, $message, $headers); 

Here I have
a) declared the subject and message as separate variables, to improve clarity and readability. 
b) joined the various POST field values together into a single string, separated by spaces.  In PHP, joining strings (also called "concatenation") is done using the .  operator - you simple place it in between two strings that you want to join to each other. 
You can add more content yourself inside the double-quoted areas, and change the subject line to your liking.