PHP5 incompatibility? Formerly good page sending values through e-mail goes bad

So I've been tasked to work with this code which used to not only echo the products ordered but also sent it via e-mail, and I can't figure out what the problem is! It worked fine before but now it's not working, which makes me suspect that it's PHP5 incompatible. It worked fine on a PHP4 server.

WHAT USED TO WORK:
Echoing of what the customer ordered and also sent an e-mail containing what the customer ordered.

WHAT WORKS NOW:
The page shows up, the order is sent, and the customer gets an e-mail from our Credit Card Gateway as well as our website stating their transaction #s, addresses and name. All the stuff covered by the previous order page.

WHAT DOESN'T WORK NOW:
What exactly they ordered (the $items array) is not being sent to the e-mail nor echoed on the page. The array is being sent to this page hence print_r($_SESSION['cart']); working, but its not being shown to the customer nor e-mailed to them.

POSSIBLE CAUSES:
Moving to a PHP5 server, unknown formatting problem.

Here's the code in its entirety, I don't even get how $email.= works for so many different things. Any help as to possible problems or incompatibilities would be greatly appreciated.

<?

ini_set('display_errors','On'); 

include 'db.php';

set_time_limit (400);

session_start();

header("Cache-control: private");


//quick fix to copy post vars

$_POST=$_SESSION['post_vars'];


print_r($_SESSION['cart']);

$itemnumms = sizeof($_SESSION['cart']);

$unique_orderid=date("dmsHyi");


$email="Thank you for ordering from Jezebelgallery.com\n\n";

$email.="Your order ID is: " . $unique_orderid . "\n\n";


$email.="Your order will take approximately 3-6 weeks to arrive. If you have any questions please call 1-866-JEZEBEL.\n\n";


$email.="Here is a list of your products:\n\n";

$num_items=0;

for($i=0;$i<$itemnumms;$i++){


 if($_VARS['action']=='rem' && $_VARS['id']==$i){

  $_SESSION['cart'][$i]="";

 }

 $val=$_SESSION['cart'][$i];

 $items= split("\|\|",$val);

 if($items[0]!=""){ 

   $query = "SELECT *,category from products,categories where categories.id=products.pid and products.id=" . $items[0];

  $result = mysql_query($query) or die("Query failed : " . mysql_error());

  $line = mysql_fetch_array($result, MYSQL_ASSOC);



$email.= stripslashes($line['category']) . ":" .  stripslashes($line['name']) . "\n";

if($line['dims']!=''){

$email.="Dimensions: " . stripslashes($line['dims']) . "\n";

}

if($items[1]!=''){ 

$email.="Glass Color: " .  stripslashes($items[1]) . "\n";

}

if($items[2]!=''){

$email.="Finish: " . stripslashes($items[2]) . "\n";

}

if($items[3]!=''){

$email.="Stocks: " .  stripslashes($items[3]) . "\n";

}

if($items[4]!=''){

$email.="Cord Color: " . stripslashes($items[4]) . "\n";

}

if($items[5]!=''){ 

 $ceiling= split("\|",stripslashes($items[5]));

 $email.="Ceiling Height: " . $ceiling[0] . "\n";

}

if($items[6]!=''){

$email.="Glass Shape: " .  stripslashes($items[6]) . "\n";

}

if($items[7]!=''){

$email.="Leaf Option: " . stripslashes($items[7]) . "\n";

}

if($items[8]!=''){

 $email.="Ceiling Cap: " . stripslashes($items[8]) . "\n";

}

  mysql_free_result($result);

  if($line['ceiling']=='Y' && $line['static']=='N'){

    $ceiling= split("\|",stripslashes($items[5]));


        $query = "SELECT * from ceiling where deleted=0 and pid=" . $items[0];

        $result2 = mysql_query($query) or die("Query failed : " . mysql_error());

        $ceil_cost = mysql_fetch_array($result2, MYSQL_ASSOC);

        $line['price']=$ceil_cost['h' . $ceiling[0]];

        mysql_free_result($result2); 

  }

  $email.="Price: $" . $line['price'] . "\n\n";

  $total+=$line['price'];

  $num_items++;

 }

}


$email.="Total # of products:" . $num_items . "\n";


//adjust the price based on discount

if($_SESSION['discount']>0){ 

  $email.="Discount:" . $_SESSION['discount'] . "%\n";

  $total=$total*((100-$_SESSION['discount'])/100);

  unset($_SESSION['discount']);

} 


//Calculate shipping as 10% of total or $15 whichever is higher

//$shipping=0.1*$total;

//if($shipping<15.00){

//  $shipping=15.00;

$idtesting = substr($val,0,4);

if($idtesting==1004)

{ $shipping=0.00;

}

if($idtesting==1005)

{ $shipping=0.00;

}

elseif($shipping<15.00){

  $shipping=15.00;

  }

  else $shipping=0.1*$total;


 $subtot=number_format($total,2);


$email.="Subtotal: $" . $subtot . "\n";


 $tax='0.00';

 if($_POST['s_state']=='NM'){

  $tax=number_format($total*0.06500,2) ;

 }

 $shipping=number_format($shipping1,2);


 if($_POST['s_state']=='NM'){

  $t= (($total*1.06500)+($shipping1));

 }else{

  $t= $total+$shipping1;

 }

 $total=number_format($t,2);

 


$email.="Tax: $" . $tax . "\n";

$email.="Shipping: $" . $shipping . "\n";

$email.="Total: $" . $total . "\n";

$email.="\n\n\n";


$email.="Your shipping information:\n\n";

$email.="First name:" .$_POST['s_fname'] . "\n";

$email.="Last name:".$_POST['s_lname'] . "\n";

$email.="Address:".$_POST['s_address'] . "\n";

$email.="City:".$_POST['s_city'] . "\n";

$email.="State:".$_POST['s_state'] . "\n";

$email.="Zip:".$_POST['s_zip'] . "\n";

$email.="Country:".$_POST['s_country'] . "\n";

$email.="Email:".$_POST['s_email'] . "\n";

$email.="Phone:".$_POST['s_phone'] . "\n";

$email.="Fax:".$_POST['s_fax'] . "\n";

$email.="Comment:".$_POST['s_comments'] . "\n";

$email.="\n\n\n";


$email.="Your billing information:\n\n";

$email.="First name:" .$_POST['b_fname'] . "\n";

$email.="Last name:".$_POST['b_lname'] . "\n";

$email.="Address:".$_POST['b_address'] . "\n";

$email.="City:".$_POST['b_city'] . "\n";

$email.="State:".$_POST['b_state'] . "\n";

$email.="Zip:".$_POST['b_zip'] . "\n";

$email.="Country:".$_POST['b_country'] . "\n";


/* let us know what happens with mail() */

/*error_reporting(2047);*/


/* The following wasn't working so I replaced it with the script from crystaltech

   i had to add the ip address 216.119.112.134 to 

   /etc/mail/relay-domains on mail.gigablast.com and restart sendmail 

   ini_set('SMTP','mail.gigablast.com');

*/

// Please specify your Mail Server - Example: mail.yourdomain.com.

ini_set("SMTP","smtp.gmail.com");


// Please specify an SMTP Number 25 and 8889 are valid SMTP Ports.

ini_set("smtp_port","25");


// Please specify the return address to use

ini_set('sendmail_from', 'jezebel@jezebelgallery.com');


$admin=$email;

/*

$admin.="Credit card information:\n\n";

$admin.="Card type:" . $_POST['card_type'] . "\n";

$admin.="Card expiration(mm/yy):" . $_POST['card_exp_m'] . "/" .  $_POST['card_exp_y'] . "\n";

$admin.="Name on card:" . $_POST['card_name']  . "\n";

$admin.="Card number:" . $_POST['card_num']  . "\n";

$admin.="Card security code:" . $_POST['card_sec']  . "\n";

*/

$subject = "jezebelgallery.com order confirmation";



/*process order*/

//process credit card

                $request=array();

        $request["x_Login"] = "1jezebel";

//        $request["x_Password"] = "Password obscured for my protection";

            $request["x_tran_key"] = "obscured for my protection";

        $request["x_Version"] = "3.0";

        $request["x_ADC_Delim_Data"] = "TRUE";

        $request["x_ADC_URL"] = "FALSE";

        $request["x_invoice_num"] = $unique_orderid;

        $request["x_cust_id"] = $unique_orderid;                

        $request["x_Card_Num"] =   $_POST['card_num'];

                $request["x_Card_Code"]= $_POST['card_sec'];

        $request["x_Exp_Date"] = $_POST['card_exp_m'] . "20" . $_POST['card_exp_y'];

        $request["x_Amount"] = $t;


        $request["x_First_Name"] = $_POST['b_fname'];

        $request["x_Last_Name"] = $_POST['b_lname'];

        $request["x_Address"] = $_POST['b_address'];

        $request["x_City"] = $_POST['b_city'];

        $request["x_State"] = $_POST['b_state'];

        $request["x_country"] = $_POST['b_country'];            

        $request["x_ZIP"] = $_POST['b_zip'];


        $request["x_ship_to_first_name"] = $_POST['s_fname'];

        $request["x_ship_to_Last_Name"] = $_POST['s_lname'];

        $request["x_ship_to_Address"] = $_POST['s_address'];

        $request["x_ship_to_City"] = $_POST['s_city'];

        $request["x_ship_to_State"] = $_POST['s_state'];

        $request["x_ship_to_country"] = $_POST['s_country'];            

        $request["x_ship_to_ZIP"] = $_POST['s_zip'];

                

        $request["x_Phone"] = $_POST['s_phone'];

        $request["x_fax"] = $_POST['s_fax'];            

        $request["x_Email"] = $_POST['s_email'];  

        //$request["x_merchant_email"] = "mickel@jezebelgallery.com";

        $request["x_merchant_email"] = "jezebel@jezebelgallery.com";


        $posturl = "https://secure.authorize.net/gateway/transact.dll?";


        $ch = new COM("MSXML2.ServerXMLHTTP"); // initalize COM Object


        // take the $request array and turn it into name=value&name=value pairs

        if (count($request) > 0) {

                reset($request);

                while (list($name, $value) = each($request)) {

                        $str .= "&".$name."=".$value;

                }

                $str = substr($str,1);

        }


/* Comment out for testing do not send data to credit card processor */

        $ch->open("POST", $posturl, false);

        $ch->setRequestHeader("User-Agent", "AUTH-PHP-API (OnlineCreator)");

        $ch->setRequestHeader("Content-Type", "application/x-www-form-urlencoded");     

        $ch->send($str);

        $results = $ch->responseText; // connect and grab the results

        //$ch->Release();

        $ch = null;

                //1 = accepted, 2 = declined, 3 = error         

        $rescode = substr($results,0,1);

                $rrc = substr($results,2,3);

        if(substr($results,0,1)=="1"){

                 /*if("1"=="1"){*/ //for testing

                 $message="Thank you for your order. A confirmation email has been sent to " . $_POST['s_email'];

                 /* To send HTML mail, you can set the Content-type header. */

                 $headers  = "MIME-Version: 1.0\r\n";

                 $headers .= "Content-type: text/html; charset=iso-8859-1\r\n";

                 //$headers .= "From: jezebel@jezebelgallery.com\r\n";

                 $headers .= "From: jezebel@jezebelgallery.com\r\n";

                 //New lines suggested by crystaltech

         $_Timestamp = date("r");

         $headers = "Date: $_Timestamp";


                 $email=str_replace("\n","<br>",$email);


// the next line is for testing

//               echo "$to $subject <html> $email </html> $headers";


// Send confirmation to person ordering

                 $to=$_POST['s_email'];

                 mail($to, $subject, "<html>" . $email . "</html>", $headers);


                 //$to = 'jezebel@jezebelgallery.com';

                 //$to = 'cynthia@immediagroup.com';

                 //$subject = "jezebelgallery.com order confirmation";

                 //mail($to, $subject, $admin, $headers);


                 //$to = 'mickel@jezebelgallery.com';

/*

                 $to = 'jezebel@jezebelgallery.com';

*/ 



// this will send confirmations to jezebel accounts activate for final update

    $to='jezebel@jezebelgallery.com,sales@jezebelgallery.com';

        mail($to, $subject, "<html>" . $email . "</html>",$headers);

                 

                 unset($_SESSION['cart']);

                }else{

                 $message="Your credit card could not be processed. Go <a href='javascript: history.go(-1)'>back</a> and make sure that all your information is correct. Full Result=" . $results;

                 /*

                 foreach($request as $a => $b){ echo "$a $b <br>";}

                 echo $results; */

                }

 // Send a copy of each order to webmaster during testing phase whether or not accepted.

    $to='brucemcintosh@gmail.com';

        //comment out next line when testing activate when testing done

    $email='Order Placed';   

    $subject=$message;

        mail($to, $subject, "<html>" . $email . "</html>",$headers);


?>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">

<html>

<head>

<title>Jezebel Gallery - Shopping Cart</title>

<meta name="author" content="dreamLogic">

<meta name="Description" content="Gallery of Santa Fe artist, painter and sculptor Jezebel.  Features one-of-a-kind stained glass lighting and home accessories.">

<meta name="Keywords" content="gallery, artist, painting, scupture, home, decor, accessories, lighting, lamps, chandeliers, sconce, custom, creative, furnishings, jewelry, santa fe, albuquerque, new mexico, nm">

<script language="JavaScript" type="text/JavaScript">

<!--

function MM_swapImgRestore() { //v3.0

  var i,x,a=document.MM_sr; for(i=0;a&&i<a.length&&(x=a[i])&&x.oSrc;i++) x.src=x.oSrc;

}


function MM_preloadImages() { //v3.0

  var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array();

    var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i<a.length; i++)

    if (a[i].indexOf("#")!=0){ d.MM_p[j]=new Image; d.MM_p[j++].src=a[i];}}

}


function MM_findObj(n, d) { //v4.01

  var p,i,x;  if(!d) d=document; if((p=n.indexOf("?"))>0&&parent.frames.length) {

    d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);}

  if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i<d.forms.length;i++) x=d.forms[i][n];

  for(i=0;!x&&d.layers&&i<d.layers.length;i++) x=MM_findObj(n,d.layers[i].document);

  if(!x && d.getElementById) x=d.getElementById(n); return x;

}


function MM_swapImage() { //v3.0

  var i,j=0,x,a=MM_swapImage.arguments; document.MM_sr=new Array; for(i=0;i<(a.length-2);i+=3)

   if ((x=MM_findObj(a[i]))!=null){document.MM_sr[j++]=x; if(!x.oSrc) x.oSrc=x.src; x.src=a[i+2];}

}


function MM_openBrWindow(theURL,winName,features) { //v2.0

  window.open(theURL,winName,features);

}


//-->

</script>

<link rel="stylesheet" href="newstyle.css" type="text/css">

<script src="rollovers.js" type="text/javascript"></script>

</head>



<body>


<!-- Customization Code -->

<!-- Remove leading // to activate custom variables -->

<script language="Javascript">

//var DOCUMENTGROUP='';

var DOCUMENTNAME='Sale';

var ACTION='01';

</script>

<!-- End of Customization Code -->

<!-- Tracking Code v3.01 - All rights reserved -->

<script language="javascript1.1" src="http://www.jezebelgallery.com/tracking.js"></script><noscript>

<img src="http://webstats.silverscopepromotion.com/p.pl?a=1000638354890&js=no" width="1" height="1"></noscript><!--//-->

<!-- End of Tracking Code -->

<p class="style3">Jezebel Gallery » Order Complete </p>

            

<?= $message ?>


                        </td>

                    </tr>

                  </table>

                  




<script type="text/javascript">

var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www.");

document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E"));

</script>

<script type="text/javascript">

try {

var pageTracker = _gat._getTracker("UA-6579606-1");

pageTracker._trackPageview();

} catch(err) {}</script>

</body>

</html>

<?                

/* Closing connection */

mysql_close($link);

//session_destroy();            

?>

I did the error reporting and the following lines show up.

Notice: Undefined index: post_vars
Notice: Undefined index: cart
Notice: Undefined index: cart
Notice: Undefined index: discount
Notice: Undefined variable: val
Notice: Undefined variable: shipping
Notice: Undefined variable: total
Notice: Undefined variable: shipping1
Notice: Undefined variable: shipping1
Notice: Undefined variable: total
Notice: Undefined variable: str
Notice: Undefined variable:
Warning: mail() [function.mail]: SMTP server response: 530 5.7.0 Must issue a STARTTLS command first. f5sm2922557wfo.4 on line 305

keep in mind I use google apps for my e-mail and the line in question is:

mail($to, $subject, "<html>" . $email . "</html>",$headers);

any suggestions? And what's weird is the undefined variables didn't have a problem back when this was PHP4. What should I do about this?