Or you can change the $email variable for some value send from a form, and the user put they self email
This is the complete PHP function for allowing the delivery of emails through an interface:
<?php
$email = "test@test.de";
/* Absender */
$absender = "Testuser <".$email.">";
/* Rueckantwort */
$reply = $email;
/* Betreff */
$subject = "Kontaktformular";
/* The Message and Colors*/
$message = '
<html>
<head>
<title>Email Test</title>
</head>
<body bgcolor="#ff4500" link="#FFD700" vlink="#FFD700" alink="#ff7813">
<table width="500" border="0" cellspacing="5" cellpadding="5">
<tr>
<td>
<p>Email Body</p>
</td>
</tr>
</table>
</body>
</html>
';
/* Email Header */
$headers .= "From: $absender";
$headers .= "Reply-To:$reply";
$headers .= "X-Mailer: PHP/".phpversion()."";
$headers .= "X-Sender-IP: $REMOTE_ADDR";
$headers .= "Content-type: Text/html";
/* Verschicken der Mail */
if(mail($email, $subject, $message, $headers)) echo "<tr><td><p>This is an email test.</p></td></tr>";
?>
<?php
$email = "test@test.de";
/* Absender */
$absender = "Testuser <".$email.">";
/* Rueckantwort */
$reply = $email;
/* Betreff */
$subject = "Kontaktformular";
/* The Message and Colors*/
$message = '
<html>
<head>
<title>Email Test</title>
</head>
<body bgcolor="#ff4500" link="#FFD700" vlink="#FFD700" alink="#ff7813">
<table width="500" border="0" cellspacing="5" cellpadding="5">
<tr>
<td>
<p>Email Body</p>
</td>
</tr>
</table>
</body>
</html>
';
/* Email Header */
$headers .= "From: $absender";
$headers .= "Reply-To:$reply";
$headers .= "X-Mailer: PHP/".phpversion()."";
$headers .= "X-Sender-IP: $REMOTE_ADDR";
$headers .= "Content-type: Text/html";
/* Verschicken der Mail */
if(mail($email, $subject, $message, $headers)) echo "<tr><td><p>This is an email test.</p></td></tr>";
?>