e-mail address not shown in proper format like myname@mycompany.com -- PHP -

i trying code php script, wherin trying send mail specified email address collect post variables java. @ first able send mails on email used warning like: message may not have been sent by: xxx@gmail.com learn more report phishing. came know need have email associated domain name, after getting 1 mails not sent warning, email address sending neither displayed , mydomainname@rsb29.rhostbh.com. how can fix this? below php script:

        $email = $_post["email"];          $pass = "0";          $pass = mysql_query("select password `seller` email = '$email'");          $myrow = mysql_fetch_array($pass);          if ($pass){              $to = $email;             $subject = "no reply, carlist password request";             $message = "hello! \n in response request password. \n\n\re-mail id: ".$email."\n\rpassword: " .$myrow[password] . "\n\n\n\r if you've received mail in error, it's user entered email address mistake while trying reset password. if didn't initiate request, don't need take further action , can safely disregard email." ;              $from = "myapp@mydomainname.com"; // changed security reason             $headers = "from:" . $from;             mail($to,$subject,$message,$headers);              echo $myrow[password];       }else{             echo 'fail';     }