note 41101 rejected from function.mail by didou

Note Submitter: sdaskin@yahoo.com ---- <?php /* recipients */ $to = "nobody@example.com" ; /* subject */ $subject = "Test mail"; /* message */ $message = ' <html> <head> <title>This is easy test</title> </head> <body> <p>WHY!why!WHY!</p> </body> </html> '; $sender = "mymail@anylongdomain.com"; // if i send with my long domain sender email nothing goes ? there is a long domain error //$sender = "mymail@sort.com"; if i use sort domain in serder it goes ! /* To send HTML mail, you can set the Content-type header. */ $headers = "MIME-Version: 1.0\r\n"; $headers .= "Content-type: text/html; charset=iso-8859-1\r\n"; /* additional headers */ $headers .= "To: nobody <nobody@example.com>\r\n"; $headers .= "From: webmaster <".$sender.">\r\n"; /* and now mail it */ mail($to, $subject, $message, $headers); ?> can any body tell me what is the problem with long domain ? i get this error in php 4.3.3 and php 4.3.4 is it a bug not not