PHP - Contact Form Script Not Sending Fields

I really need some help.  I am very new to PHP and I've been stuck for a couple of days.  I created a contact form and everything seems to be working correctly, except the mail is showing it's sent, but I never receive an email in my Inbox or Spam folder.  Can someone please review my code?

Here is the PHP:

<?php
  // DEFINE VARIABLE AND SET EMPTY VALUES
  $varfnameErr = $varlnameErr = $varemailErr = $varphoneErr = $varpositionErr = "";
  $varfname = $varlname = $varemail = $varphone = $varposition = $success = "";

  
  //FORM SUBMITTED WITH POST METHOD
  if ($_SERVER["REQUEST_METHOD"] == "POST") {

    //VALIDATE FIRST NAME
    if (empty($_POST["varfname"])) {
      $varfnameErr = "First Name is required";
    } else {
      $varfname = test_input($_POST["varfname"]);
      // MAKE SURE FIRST NAME ONLY CONTAINS LETTERS AND WHITE SPACE
      if (!preg_match("/^[a-zA-Z ]*$/",$varfname)) {
        $varfnameErr = "Only letters and white space are allowed";
      }
    }

    //VALIDATE LAST NAME
    if (empty($_POST["varlname"])) {
      $varlnameErr = "Last Name is required";
    } else {
      $varlname = test_input($_POST["varlname"]);
      // MAKE SURE LAST NAME ONLY CONTAINS LETTERS AND WHITE SPACE
      if (!preg_match("/^[a-zA-Z ]*$/",$varlname)) {
        $varlnameErr = "Only letters and white space are allowed";
      }
    }
  
    //VALIDATE EMAIL ADDRESS
    if (empty($_POST["varemail"])) {
      $varemailErr = "Email Address is required";
    } else {
      $varemail = test_input($_POST["varemail"]);
      // MAKE SURE EMAIL ADDRESS IS FORMATTED CORRECTLY
      if (!filter_var($varemail, FILTER_VALIDATE_EMAIL)) {
        $varemailErr = "Invalid email address format";
      }
    }

    //VALIDATE PHONE NUMBER
    if (empty($_POST["varphone"])) {
      $varphoneErr = "Phone number is required";
    } else {
      $varphone = test_input($_POST["varphone"]);
      // MAKE SURE PHONE NUMBER IS IN CORRECT FORMAT
      if (!preg_match("/^(\d[\s-]?)?[\(\[\s-]{0,2}?\d{3}[\)\]\s-]{0,2}?\d{3}[\s-]?\d{4}$/i",$varphone)) {
        $varphoneErr = "Invalid telephone format";
      }
    }
	
    //VALIDATE POSITION
    if (empty($_POST["varposition"])) {
      $varpositionErr = "Position is required";
    } else {
      $varposition = test_input($_POST["varposition"]);
    }

    //IF ALL DATA IS CORRECT
    if ($varfnameErr == '' and $varlnameErr == '' and $varemailErr == '' and $varphoneErr == '' and $varpositionErr == '') {
      $message_body = '';
      unset($_POST['submit']);

      //THIS IS JUST FOR TESTING PURPOSES
      $message_body = $varfname;

      //foreach ($_POST as $key => $value) {
      //    $message_body .= "$key: $value\n";
      //}
      $to = 'mygmail@gmail.com';
      $subject = 'Volunteer Form Submission';
      
      $message = wordwrap($message_body, 70);
      $headers  = 'MIME-Version: 1.0' . "\r\n"; 
      $headers .= 'Content-type: text/html; charset=utf-8' . "\r\n";
      $headers .= "From: " . $varemail . "\r\n";
      $subject = 'Volunteer Form Submission';
      $to = 'mygmail@gmail.com';
      $result = mail($to, $subject, $message, $headers);
      //THIS RETURNS "1"
      print $result;
      
      //IF ALL DATA IS CORRECT MAKE SURE EMAIL WAS SENT
      if (mail($to, $subject, $message, $headers)) {
        $success = "Message sent. Thank you contacting us! We will reply as soon as possible.";
        $varfname = $varlname = $varemail = $varphone = $varposition = "";
      } else {
        $success = "Something went wrong!";
      }
    }
  }

//STRIP UNWANTED CHARACTERS FROM VARIABLES
function test_input($data) {
  $data = trim($data);
  $data = stripslashes($data);
  $data = htmlspecialchars($data);
  return $data;
}
?>

Here is the HTML:

    <div class="row regformrow">
      <div class="coffee-span-12 regformcolumn">
        <div class="subgrid regformsubgrid">
          <div class="row regformsubgridheaderrow">
            <div class="coffee-span-12 regformsubgridheadercolumn">
              <h4 class="regformsubgridheadertitle">Volunteer Form</h4>
            </div>
          </div>
          <div class="row regformsubgridrow">
            <form class="form-container regformsubgridformcontainer" action=<?= $_SERVER['PHP_SELF']; ?> method="post">
              <div class="coffee-span-4 coffee-972-span-6 coffee-458-span-12 regformsubgridcolumn1">
                <div class="container regformsubgridcontainer1">
                  <label class="label form-label-all"><span style="font-style:italic;color:#FF5454;">* Required Fields</span></label></br>
                  <div class="formfieldgroup">
                    <input class="fname" name="varfname" type="text" tabindex="1" placeholder="First Name" value="<?= $varfname; ?>"><span class="requiredfield"> *</span>
                    <span class="form-error"><?= $varfnameErr ?></span>
                  </div>
                  <div class="formfieldgroup">
                    <input class="lname" name="varlname" type="text" tabindex="2" placeholder="Last Name" value="<?= $varlname; ?>"><span class="requiredfield"> *</span>
                    <span class="form-error"><?= $varlnameErr ?></span>
                  </div>
                  <div class="formfieldgroup">
                    <input class="email" name="varemail" type="text" tabindex="2" placeholder="Email Address" value="<?= $varemail; ?>"><span class="requiredfield"> *</span>
                    <span class="form-error"><?= $varemailErr ?></span>
                  </div>
                  <div class="formfieldgroup">
                    <input class="phone" name="varphone" type="text" tabindex="2" placeholder="Telephone Number" value="<?= $varphone; ?>"><span class="requiredfield"> *</span>
                    <span class="form-error"><?= $varphoneErr ?></span>
                  </div>
                  <div class="formfieldgroup">
                    <select class="select selectbox" name="varposition" id="varposition" tabindex="5"><option value="">Select one...</option><option value="Chaperone">Chaperone</option><option value="Class Monitor">Class Monitor</option><option value="Parking Attendant">Parking Attendant</option><option value="Party Coordinator">Party Coordinator</option><option value="Teacher Aid">Teacher Aid</option></select><span class="requiredfield"> *</span>
                    <span class="form-error"><?= $varpositionErr ?></span>
                  </div>
                  <div class="formfieldgroup">
                    <input class="test" name="test" type="text" tabindex="6" placeholder="If you are human, leave this field blank" value="">
                  </div>
                  <div class="formfieldgroup">
                    <button type="submit" class="button-submit-1" name="submit" tabindex="7" data-submit="...Sendng">Submit</button>
                  </div>
                  <div class="formfieldgroup">
  				  <div class="success"><?= $success; ?></div>
                  </div>
                </div>
              </div>
            </form>
          </div>
        </div>
      </div>
    </div>

Hello,

Can someone help me with these contact-form please,

I just want to include a file (.pdf, .jpg, .png) and send the mail.

For the moment, the mail is send but not with the file included.

Here is the website

http://www.coeuraprendre.art

HTML CODE :

<form id="contact-form" class="checkform" action="#" target="contact-send.php" method="post" enctype="multipart/form-data" >
				
						<div class="form-row clearfix">
							<label for="name" class="req">Nom *</label>
							<input type="text" name="name" class="name" id="name" value="" placeholder="Name" />
						</div>
						
						<div class="form-row clearfix">
							<label for="email" class="req">Email *</label>
							<input type="text" name="email" class="email" id="email" value="" placeholder="Email"/>
						</div>
						
						<div class="form-row clearfix textbox">
							<label for="message" class="req">Nom du projet  *</label>
							<textarea name="message" class="message" id="message" rows="15" cols="50" placeholder="Message"></textarea>
						</div>
						
							<div class="form-row clearfix">
							<label for="pdf" class="req">Ajoutez votre dossier d'inscription (Pdf intéractif) *</label>
							<input type="file" id="pdf" class="pdf" name="pdf" placeholder="Pdf" accept="image/pdf">

						</div>
						
						
						
						
						<div id="form-note">
							<div class="alert alert-error">
								<strong>Error</strong>: Please check your entries!
							</div>
						</div>
						
						<div class="form-row form-submit">
							<input type="submit" name="submit_form" class="submit" value="Send" />
						</div>
				
						<input type="hidden" name="subject" value="From Coeur à Prendre" />
						<input type="hidden" name="fields" value="name,email,message," />
						<input type="hidden" name="sendto" value="info@coeuraprendre.art" />  
					</form> 
				</div>
				<!-- Contact form -->

PHP CODE :

<?php

define("WEBMASTER_EMAIL", $_POST['sendto']);
if (WEBMASTER_EMAIL == '' || WEBMASTER_EMAIL == 'Testemail') {
	die('<div class="alert alert-confirm"> <h6><strong>The recipient email is not correct</strong></h6></div>');	
} 

define("EMAIL_SUBJECT", $_POST['subject']);
if (EMAIL_SUBJECT == '' || EMAIL_SUBJECT == 'Subject') {
	define("EMAIL_SUBJECT",'Contact');	
}

$name = stripslashes($_POST['name']);
$email = trim($_POST['email']);
$message = stripslashes($_POST['message']);
$pdf = stripslashes($_POST['pdf']);


$custom = $_POST['fields'];
$custom = substr($custom, 0, -1);
$custom = explode(',', $custom);

$message_addition = '';
foreach ($custom as $c) {
	if ($c !== 'name' && $c !== 'email' && $c !== 'message' && $c !== 'pdf' && $c !== 'subject') {
		$message_addition .= '<b>'.$c.'</b>: '.$_POST[$c].'<br />';
	}
}

if ($message_addition !== '') {
	$message = $message.'<br /><br />'.$message_addition;
}


$message = '<html><body>'.nl2br($message)."</body></html>";
$mail = mail(WEBMASTER_EMAIL, EMAIL_SUBJECT, $message,
     "From: ".$name." <".$email.">\r\n"
    ."Reply-To: ".$email."\r\n"
    ."X-Mailer: PHP/" . phpversion()
	."MIME-Version: 1.0\r\n"
	."Content-Type: text/html; charset=utf-8");


if($mail)
{
echo '
		<div class="alert alert-confirm">
			<strong>Confirm</strong>: Your message has been sent. Thank you!
		</div>
';
}
else
{
echo '
		<div class="alert alert-error">
			<strong>Error</strong>: Your message has not been send!
		</div>
';
}

?>

<?php

// Email address verification
function isEmail($email) {
    return(preg_match("/^[-_.[:alnum:]]+@((([[:alnum:]]|[[:alnum:]][[:alnum:]-]*[[:alnum:]])\.)+(ad|ae|aero|af|ag|ai|al|am|an|ao|aq|ar|arpa|as|at|au|aw|az|ba|bb|bd|be|bf|bg|bh|bi|biz|bj|bm|bn|bo|br|bs|bt|bv|bw|by|bz|ca|cc|cd|cf|cg|ch|ci|ck|cl|cm|cn|co|com|coop|cr|cs|cu|cv|cx|cy|cz|de|dj|dk|dm|do|dz|ec|edu|ee|eg|eh|er|es|et|eu|fi|fj|fk|fm|fo|fr|ga|gb|gd|ge|gf|gh|gi|gl|gm|gn|gov|gp|gq|gr|gs|gt|gu|gw|gy|hk|hm|hn|hr|ht|hu|id|ie|il|in|info|int|io|iq|ir|is|it|jm|jo|jp|ke|kg|kh|ki|km|kn|kp|kr|kw|ky|kz|la|lb|lc|li|lk|lr|ls|lt|lu|lv|ly|ma|mc|md|mg|mh|mil|mk|ml|mm|mn|mo|mp|mq|mr|ms|mt|mu|museum|mv|mw|mx|my|mz|na|name|nc|ne|net|nf|ng|ni|nl|no|np|nr|nt|nu|nz|om|org|pa|pe|pf|pg|ph|pk|pl|pm|pn|pr|pro|ps|pt|pw|py|qa|re|ro|ru|rw|sa|sb|sc|sd|se|sg|sh|si|sj|sk|sl|sm|sn|so|sr|st|su|sv|sy|sz|tc|td|tf|tg|th|tj|tk|tm|tn|to|tp|tr|tt|tv|tw|tz|ua|ug|uk|um|us|uy|uz|va|vc|ve|vg|vi|vn|vu|wf|ws|ye|yt|yu|za|zm|zw)$|(([0-9][0-9]?|[0-1][0-9][0-9]|[2][0-4][0-9]|[2][5][0-5])\.){3}([0-9][0-9]?|[0-1][0-9][0-9]|[2][0-4][0-9]|[2][5][0-5]))$/i", $email));
}

if( ! empty($_POST)) {

    // Enter the email where you want to receive the message
    $emailTo = 'email@testing.com;

    $clientName = trim($_POST['name']);
    $clientEmail = trim($_POST['email']);
    $subject = trim($_POST['subject']);
    $message = trim($_POST['message']);

    $array = array();
    $array['nameMessage'] = '';
    $array['emailMessage'] = '';
    $array['messageMessage'] = '';

    if($clientName == '') {
        $array['nameMessage'] = 'Please enter your name.';
    }
    if(!isEmail($clientEmail)) {
        $array['emailMessage'] = 'Please insert a valid email address.';
    }
    if($message == '') {
        $array['messageMessage'] = 'Please enter your message.';
    }

    if($clientName != '' && isEmail($clientEmail) && $message != '') {
        // Send email
	$headers = "From: " . $clientName . " <" . $clientEmail . ">" . "\r\n" . "Reply-To: " . $clientEmail;
	mail($emailTo, $subject, $message, $headers);
    }

    echo json_encode($array);

}

?>