you cant point out at any nationalities like this for not responding your email.. your email may be important to YOU and needs a quick response but u cant dictate the same from the opposite side... if its unimportant for them then they wont, as simple as that... but it looks bit stupid to me for you asking why Qatari nationals dont reply to your email???!!!! so u get flashing reply for your own nationalities???? so it simply depends on the person and not on nationals... mind you, you are in Qatar mate... :-)