After landing at Seattle airport by Alaska airlines from Denver; how much time is generally required for boarding in Emirates Airlines going to Dubai.

First I would get there asap, then you would have time to relax and have a meal.

Having done this, but not to Dubai but other international flights my recommendation not knowing arrival and departure times or how busy the airport will be at the particular time going from Domestic to International. At least one hour if bags are being transferred onto the next flight and an hour and half at least if you must go through baggage claim maybe two to be safe. I like to be a bit cautious.

For all connecting flights you have to be at the boarding gate 25 minutes before the deaparature. It usually takes 45 minutes for all the formalities but don't quote me on this.

Smart and practical answer Karen ..