I am trying to send a registration confirmation mail from my site to user who are registering from my site.

my code is:-

  $drg_name = addslashes(trim($_POST['drg_name']));
      $drg_surname = addslashes(trim($_POST['drg_surname']));
      $drg_email = addslashes(trim($_POST['drg_email']));
      $drg_username = addslashes(trim($_POST['drg_username']));
      $drg_pass = addslashes(base64_encode($_POST['drg_pass']));
      $drg_addr1 = addslashes(trim($_POST['drg_addr1']));
      $drg_addr2 = addslashes(trim($_POST['drg_addr2']));
      $drg_addr3 = addslashes(trim($_POST['drg_addr3']));
      $drg_town = addslashes(trim($_POST['drg_town']));
          $drg_county = addslashes(trim($_POST['drg_county']));
      $drg_zip = addslashes(trim($_POST['drg_zip']));
      $drg_country = addslashes(trim($_POST['drg_country']));
      $drg_phone = addslashes(trim($_POST['drg_phone']));
      $drg_gender = addslashes(trim($_POST['drg_gender']));
          $drg_pstatus = addslashes(trim($_POST['drg_pstatus']));
      $drg_dod = addslashes(trim($_POST['drg_dod']));
      $drg_dom = addslashes(trim($_POST['drg_dom']));
      $drg_doy = addslashes(trim($_POST['drg_doy']));
      $drg_dob=$drg_dod.'/'.$drg_dom.'/'.$drg_doy;
          $drg_question = addslashes(trim($_POST['drg_question']));
          $drg_answer = addslashes(trim($_POST['drg_answer']));


    //send confirmation email to user to activate his/her acc


        $encoded_usr_id=base64_encode($usr_id);

        $en_id=base64_encode($insert_id);

    $subject = "Confirmation From dragonsnet.biz" ;

        $message = "Thank you to register with dragonsnet.biz<br>\n In order to >activate your account please click here:

http://My SITE URL/registration_success.php?envar=".$encoded_usr_id."&euid=".$en_id."'> Activate
\n

Thank you for taking the time to register to the dragonsnet.biz Website. ";

    $this->_globalObj->send_email('support@ MY-Site', $drg_email, $subject, $message, 'Site Name');
    $cnf=base64_encode("confirmation");
    die($this->_globalObj->redirect("registration_confirmation.php?eml=$cnf"));

}

my mail is going in user mail ID but in Spam not in inbox. Please help

Thanks In Advance.