<?php 
if ($_POST) {//Formdan veri gönderildiyse 

    $mailadres=$_POST["mail"]; 
	$seninmail = "mailadresin@xx.com";
	$konu = "test";
	if (mail("$seninmail","$konu","$mailadres"))
	{
	echo "Mail gönderildi.";
    }
	else{
echo "Mail gönderilemedi";
} }
else{	
        ?> 
  <form id="iletisim" name="iletisim" method="post" action="index.php">

E-Mail:<input name="mail" type="text" class="text" id="textfield" size="42" />

<input name="button" type="submit" id="button" value="Gonder " />
</form>        <?php 
        } 
?>