Arkadaşlar mail attıktan sonra

--- The following addresses had delivery problems ---

<huri.kaya@tvem.com.tr> (This server requires PTR for unauthenticated connections.)
Original-Recipient: <huri.kaya@tvem.com.tr>
Action: failed
Diagnostic-Code: smtp; 554 This server requires PTR for unauthenticated connections.
Remote-MTA: 92.42.39.165

tarzı hata alıyoruz. Sebebi ne olabilir?