PHPMailer不从smtp主机发送

I'm using PHPMailer and I set it up to use SMTP for sending emails. The problem is, it's not connecting to the SMTP server but instead its trying to send mail from the hosting server. Heres the code i created:

                $mail = new PHPMailer ( true );
                $mail->IsSMTP ();
                $mail->Host = $res ['outgoingmailserverhost'];
                if(in_array($res['outgoingmailserverencryptedconnectiontype'],array('ssl','tls'))){
                    $mail->SMTPSecure = $res ['outgoingmailserverencryptedconnectiontype'];
                }
                $mail->SMTPDebug = 2;
                $mail->SMTPAuth = true;
                $mail->Port = ( int ) $res ['outgoingmailserverport'];
                $mail->Username = $imapUser;
                $mail->Password = $imapPass;
                $mail->SetFrom($fromaddress,$fromname);
                $mail->AddReplyTo($fromaddress,$fromname);
                foreach($allrecipients as $type=>$recip){
                    foreach($recip as $recs){
                        if($type==='cc'){
                            $mail->AddCC($recs);
                        } elseif($type==='bcc'){
                            $mail->AddBCC($recs);
                        } elseif($type==='to'){
                            $mail->AddAddress($recs);
                        }
                    }
                }
                $mail->Subject = $subject;
                $mail->AltBody = $textbody;
                $mail->MsgHTML($htmlbody);
                if($attachment1!==null){
                    $attachment1= BASE_PATH . '/data/uploads/' . $attachment1;
                    $mail->AddAttachment($attachment1);
                }
                if($attachment2!==null){
                    $attachment2= BASE_PATH . '/data/uploads/' . $attachment2;
                    $mail->AddAttachment($attachment2);
                }
                if($attachment3!==null){
                    $attachment3= BASE_PATH . '/data/uploads/' . $attachment3;
                    $mail->AddAttachment($attachment3);
                }
                $mail->Send();

I fixed it by commenting out $mail->IsSMTP()