PhpMailer不使用html

Question

I am using PhpMailer class to send emails that contains html,I noticed that if the body on email contain img tags the email not receiving and no errors showing.

Any suggestions?

my code so far:

            $mail = new PHPMailer();
            $mail->IsSMTP();
            $mail->SMTPAuth = true;
            $mail->SMTPSecure = 'ssl';
            $mail->Host = "smtp.gmail.com";
            $mail->Port = 465;

            $mail->Username = "myusername";
            $mail->Password = "mypassword";


                $mail->setFrom($from);
                $mail->addAddress($to);

            $mail->Subject = $subject;
            $mail->Body =$body;
            $mail->IsHTML(true); 

            if ($mail->send()) {
                return 1;
            } else {

                return 0;
            }