Xchange 2k delay sending/receiving email

I dont know what else to do. My exchange server is sends and receives emails with a few hours delay, i though it was a question of all the spamming i am getting but know i doub it. Yesterday when i took a look into the smtp queue i realize i had like 7000 msg in the “awaiting for diretory lookup” queue, now i am tryin to look in the smtp queue but it takes for ever to show me the screen…any help, guide… or fast way of killing my self!!!
thanks