PHP not sending emails!!

Hello,

I have a yahoo hosting account with the email info@pictureperfectdvdmedia.com. Using PHP, I would like all of the email through my flash contact form be sent to that email address. When I send them from my computer via my website, I receive them (after 40-45 minutes), but anyone else using their computer, I cannot receive their email from the flash contact form.

Below is the PHP code. ANY SUGGESTIONS!??

Thanks,

Lawrence

<?php
$headers = "MIME-Version: 1.0\r\n";
$headers .= "Content-type: text/html; charset=iso-8859-1\r\n";
if(empty($_POST['senderEmail'])){
echo"no email address found";
exit;
}
$senderName = $_POST['senderName'];
$senderEmail = $_POST['senderEmail'];
$senderLocate = $_POST['senderLocation'];
$senderMsg = nl2br($_POST['senderMsg']);
$senderRpl = $_POST['senderRpl'];
$sitename = "Picture Perfect DVD Media";
$to = "info@pictureperfectdvdmedia.com";
$ToName = "Picture Perfect DVD Media";
$date = date("m/d/Y H:i:s");
$ToSubject = "Inquiry From $senderName / $senderEmail via $sitename";
$EmailBody = "A visitor to $sitename has left the following information<br />
Sent By: $senderName
<br /><br />
Message Sent:
<br />$senderMsg<br /><br />
Require reply: $senderRpl
<br />";
$EmailFooter = "<br />Sent: $date<br />Location:$senderLocate<br />";
$Message = $EmailBody.$EmailFooter;
$ok = mail($to, $ToSubject, $Message, $headers . "From:$to");
if($ok){
echo "retval=1";
}else{
echo "retval=0";
}

?>