html5 - String / Array error on PHP form -

i'm finishing project can't seem see went wrong on php form. me correct yet i'm getting error.

warning: mail() expects parameter 4 string, array given in /customers/f/a/b/webpx.be/httpd.www/sendemail.php on line 15

my php form:

<?php $name       = @trim(stripslashes($_post['name']));  $email      = @trim(stripslashes($_post['email']));  $message    = @trim(stripslashes($_post['message']));  $to         = 'email@email.com';//replace email  $headers   = array(); $headers[] = "mime-version: 1.0"; $headers[] = "content-type: text/plain; charset=iso-8859-1"; $headers[] = "from: {$name} <{$from}>"; $headers[] = "reply-to: <{$from}>"; $headers[] = "subject: {$subject}"; $headers[] = "x-mailer: php/".phpversion();  mail($to, $subject, $message, $headers);  die;  ?>  <?php if ($_post['submit']) {     if (mail($to, $subject, $message, $headers)) {          echo '<p>thank email! contact soon.</p>';     }      else {          echo '<p>oops! error occurred. try sending message again.</p>';      } } ?>  <style type="text/css">     p{text-align:center;font-size:50px;background:#0091a2;margin-top:30px;padding:20px;width:500px;margin:0 auto;color:#fff} </style> 

my html:

<form method="post" action="sendemail.php" onsubmit="return validation();">                             <div class="row">                                 <div class="form-group col-md-6">                                     <input type="text" name="name" class="form-control" placeholder="voornaam + familienaam" required="required">                                 </div>                                 <div class="form-group col-md-6">                                     <input type="email" name="email" class="form-control" placeholder="e-mail" required="required">                                 </div>                                 <div class="form-group col-md-12">                                     <textarea rows="6" name="message" class="form-control" placeholder="uw boodschap ..." required="required"></textarea>                                 </div>                                 <div class="form-group col-md-12">                                   <button type="submit" class="btn btn-lg btn-dark-bg" data-loading-text="sending...">verstuur bericht</button>                                 </div>                             </div>                         </form> 

the thing think can wrong "to" in form. point me in right direction please?

thx in advance!

$headers in array , needs string. each header should separated new line. implode() string newline character:

$headers   = array(); $headers[] = "mime-version: 1.0"; $headers[] = "content-type: text/plain; charset=iso-8859-1"; $headers[] = "from: {$name} <{$from}>"; $headers[] = "reply-to: <{$from}>"; $headers[] = "subject: {$subject}"; $headers[] = "x-mailer: php/".phpversion(); $headers = implode("\r\n", $headers);  mail($to, $subject, $message, $headers);