在电子邮件中接收未填写的联系表格

so in the last 2 months my website is online, i have been received 2 normal email from my contact form and like 30 empty unfilled form emails. I also use validator http://faireware.de/js/jquery.form-validation-and-hints.js. The weird is that i don't get these empty for emails when i i.e. dont fill an form and press send. It happens automaticly somehow... a spam bots or something, could it be?

My HTML code is:

<form method="post" action="contactengine.php">

  <div class="field required">
    <p>Name<br>
    <input class="text verifyText hint" name="name" type="text" size="25" title="*Ihr Name..."></p>
  </div><!--/field--> 

  <div class="field required ">
    <p>E-Mail<br>
    <input class="email verifyMail hint " name="email" type="text" size="25" title="*Ihre E-Mail-Adresse..."></p>
    </div><!--/field-->

    <div class="field required ">
      <p>Nachricht<br>
      <textarea name="message" rows="50" cols="50" title="*Schreiben Sie Ihre Nachricht..." class="hint "></textarea></p>
    </div><!--/field-->
  <p><input class="submit" type="submit" value="Senden"></p>
</form>

and my contactengine.php is:

<?php

$Subject = "Kontaktformular - FaireWare";
$Name = Trim(stripslashes($_POST['name'])); 
$Email = Trim(stripslashes($_POST['email'])); 
$Message = Trim(stripslashes($_POST['message'])); 
$EmailFrom = $Email;
$EmailTo = "info@faireware.de";

// validation
$validationOK=true;
if (!$validationOK) {
  print "<meta http-equiv=\"refresh\" content=\"0;URL=error.htm\">";
  exit;
}

// prepare email body text
$Body = "";
$Body .= "Name: ";
$Body .= $Name;
$Body .= "

";
$Body .= "E-Mail: ";
$Body .= $Email;
$Body .= "

";
$Body .= "Nachricht: ";
$Body .= "
";
$Body .= $Message;
$Body .= "

";

// send email 
$success = mail($EmailTo, $Subject, $Body, "From: $Email");

// redirect to success page 
if ($success){
  print "<meta http-equiv=\"refresh\" content=\"0;URL=contactthanks.html\">";
}
else{
  print "<meta http-equiv=\"refresh\" content=\"0;URL=error.htm\">";
}
?>

And the empty email forms do come like this:

Name: 

E-Mail: 

Nachricht:

Does it do it automaticly and how can it surpass validation...? I don't know PHP and very little java, so does anyone have any idea where the problem could be?

Thank you!