Php Mail Function Not Working! - I can't get the mail function work and I can't figure out why.

<?php

//I don't know how to explain this on English, you should get what this does after a few looks :D "nimi" is the name and "arvo" is value, I think something is wrong with them but I don't know what!

foreach($_POST as $nimi => $arvo) {
   $palaute .= $nimi . ": " . $arvo . "\n";
}

//Send the comment to email by php "mail" function
$viesti = mail("my-email@myemail.com", "Palaute", $palaute);

//$viesti is true when email is sent succesfully
if($viesti) {
   //when sent succesfully, it redirects to the thank you page
   header("Location: ../kiitos.php");
} else {
   //If not, it will redirect to the error page
   header("Location: ../virhe.php");
}
?>

<form action="mymail.php" method="post">
Enter your Name:<input type="text" name="name" /> <br />
Enter your Email:<input type="text" name="email" /> <br />
Enter your Message:<textarea name="message"> Enter your message here</textarea><br />
<input type="submit" value="Submit" />
</form>

<?php

//you can use your foreach here but that is confusing

$name=$_POST['name'];              //this will receive the name
$email=$_POST['email'];            //this will receive the email address you mentioned
$message=$_POST['message'];        //receives the textarea

$recipent="yourname@yourdomain.com";   //you should set this in your local smtp server...this is to in mail function
$subject="user details form";          //this is subject

//This is the main mistake you made I think...you must have From header in your mail funcion or you should set it in php.ini file.

$header="From:$name";                     //From header is must
$header .= "Reply-To:$email";             //jsut adding headers

$send=mail($recipent, $subject, $message, $header) or die("failure");  //recipent, subject and message are must

if($send)
echo "success";
?>

<?php
if(isset($_REQUEST['Submit']))
{
        @extract($_POST);
      
            $subject=$subject;
          
$msg="Name:".$name."\n"."Email:".$email."\n"."Message:".$msg;
$to="yourmail@yahoo.com";        
$headers .= "Reply-to: $headers4\n";
$headers .= "From: $email\n";
$headers .= "Errors-to: $headers4\n";
    if(mail("$em","Query!!!","$msg \n \n Site Admin","$headers"))
  
    {
  
    $massage1="<center><font face='Verdana' size='2' ><b>THANK YOU</b> <br>Your email has been sent successfully..</center>";
    }
    else{
  
    echo " <center><font face='Verdana' size='2' color=red >There is some system problem in sending login details to your address. Please contact Site Admin. <br></center></font>";
  
    }
}      

?>
<table width="99%" border="0" align="center" cellpadding="0" cellspacing="5" bgcolor="#CCCCFF">
              <form method="post" action="Contactus.php" enctype="multipart/form-data" name="form" >
              <tr>
                <td width="27%" align="right" class="form_text">Name<span class="price_text">*</span> </td>
                <td width="73%" align="left"><input name="name" type="text" class="form_text_area" id="name" maxlength="32" /></td>
              </tr>
              <tr>
                <td align="right" class="form_text">Email<span class="price_text">*</span> </td>
                <td align="left"><input name="email" type="text" class="form_text_area" id="email" maxlength="32" /></td>
              </tr>
              <tr>
                <td align="right" class="form_text">Subject<span class="price_text"> *</span></td>
                <td align="left"><input name="subject" type="text" class="form_text_area" id="subject" maxlength="32" />                </td>
              </tr>
              <tr>
                <td align="right" class="form_text">Message<span class="price_text"> *</span></td>
                <td align="left"><label>
                  <textarea name="msg" cols="30" rows="10" id="msg"></textarea>
                </label></td>
              </tr>
              <tr>
                <td align="right" class="form_text">&nbsp;</td>
                <td align="left"><label>
                  <input type="submit" name="Submit" value="Submit" />
                </label></td>
              </tr>
</form></table>