For context, I don't report to this colleague. He has asked me to help with something that is strictly speaking beyond my remit but won't take long. I'm happy to help out colleagues, junior or senior when I can and most of them have the courtesy to manage a please/thank you when they email me. I'm honestly not expecting effusive gratitude for everything but this particular manager seems to think he is too important to bother with even basic manners. Or am I expecting too much?