Running curl twice in php

I'm trying to send email via php mail function like below but it doesn't seem to work on IE. It works on all other browsers. Below is the code. Is there a reason why???

$sent1 = mail($to, $subject, $message, $headers);
$sent2 = mail($clientTo, $clientSubject, $clientMessage, $clientHeaders);
if ($sent1 && $sent2){
                    $ch = curl_init("https://www.salesforce.com/servlet/servlet.WebToLead?encoding=UTF-8");
                    curl_setopt($ch, CURLOPT_POST, 1);
                    curl_setopt($ch, CURLOPT_POSTFIELDS, "oid=$sf_oid&first_name=$sf_first_name&last_name=$sf_last_name&company=$sf_company&phone=$sf_phone&email=$sf_email&URL=$sf_website&descr开发者_Go百科iption=$sf_description&lead_source=$sf_leadsource");
                    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
                    curl_exec($ch);
                    $info = curl_getinfo($ch);
                    if($_SERVER['REMOTE_ADDR'] == "124.254.75.167")
                        //print_r($info);
                    curl_close($ch);

                    $ch = curl_init("http://www.rankreport.com.au/ajax/add_new_lead");
                    curl_setopt($ch, CURLOPT_POST, 1);
                    curl_setopt($ch, CURLOPT_POSTFIELDS, "lead_company_id=1&lead_business=1234&lead_first_name=asdf&lead_website=12314.com&lead_phone=1234&lead_email=test@test.com&lead_package=seo");
                    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
                    curl_exec($ch);
                    curl_close($ch);

                    echo '3';
                }

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PHP has nothing to do with browser (PHP is server-side executable), so it isn't browser's problem. You have probably no $sent1, $sent2 defined