The cupboard above the range usually just hides the vent so really not for storage.but if you mean an under cabinet microwave exhaust they are really quite useless.

T hat is just what the lazy person with no planning or forethought gets.

Often, poor planning also gets you an exhaust duct that violates codes for "smooth interior surface" as shown below.

M1503.1 General.

Range hoods shall discharge to the outdoors through a single-wall duct. The duct serving the hood shall have a smooth interior surface, shall be air tight, shall be equipped with a back-draft damper, and shall be independent of all other exhaust systems. Ducts serving range hoods shall not terminate in an attic or crawl space or areas inside the building.

http://publicecodes.cyberregs.com/icod/irc/2012/icod_irc_2012_15_sec003.htm

It is actually possible to use the horizontal option on most hoods and microwaves. You can even use a 3.25" × 14" rectangle duct to go up through the wall if you need to exhaust vertically.