I have added the following contact form to my site however when I use the code it records that an email has been sent but no email is received at the respective email address.

Is there anything I need to set up email system to work other than just the code on the page?

<table width="400" border="0" cellpadding="0" cellspacing="1"  bgcolor="#EDEDED" border="1">
<td><form name="form1" method="post" action="contactsend.php">
<table width="100%" border="0" cellspacing="1" cellpadding="3">
<td width="82%"><input name="subject" type="text" id="subject" size="50"></td>
<td><textarea name="detail" cols="50" rows="10" id="detail"></textarea></td>
<td><input name="name" type="text" id="name" size="50"></td>
<td><input name="customer_mail" type="text" id="customer_mail" size="50"></td>
<td><input type="submit" name="Submit" value="Submit"> <input type="reset" name="Submit2" value="Reset"></td>

// Contact subject
$subject ="$subject"; 
// Details

// Mail of sender
// From 
$header="from: $name <$mail_from>"; 

// Enter your email address
$to ='*****@****.com'; 


// Check, if message sent to your email 
// display message "We've recived your information"
echo "Thank You for Contacting Us. We will endevour to reply as soon as possible.";
else {
echo "ERROR";