i have being configuring MK for long time now, seem to be working well for me except for some situation that often occur which i gave me embarrasment from customer i work for…
Recently i configure MK 2.9.8 i notice that when a user on the local network try to attach a file with yahoo mail or any mail services it give excessive timer out as a result of this make other user not to be able to access the web or any other thing untill the user doing attachment is done, also with dns server configuration i configure it it work for a period of time and fail until i rebooted the mikrotik for how long will i be rebooting 
pls help me with this problem
I have the same issue with the 2.9.X version.
I’m wondering for DNS requests that are very slow.
ciao
Max