Hi Marcia, you can spray paint the cupboards. I spray painted a metal locker and love how it turned out.
Spray paint is a great option! Make sure that the metal is properly cleaned and has a couple of coats of primer on it for best results. I prefer using a Rusty Metal primer because this give the best surface for spray paint. Good luck with your project - I hope this helps!
This might help you https://www.hometalk.com/28074888/how-to-paint-metal-lockers
Use a paint specifically made for metal. Ask at you local paint store. Use a foam roller eliminates brush strokes.
Use a metal primer first then your paint. Best wishes.
You'll need to clean them really well, patch any damage, most likely prime and then use a paint for metal. Ask at the paint counter for the right products for your situation.