Exactly what kind of trailer? Boat? Travel trailer? I tow a boat all the time. Around 4,000 lbs. 2012 should be rated to tow around 8,000 lbs. Tongue weight is the biggest thing to watch. Raptors have a soft suspension so the back of the truck will squat a bit. Can be helped with different leaf springs and a weight distribution hitch. Try not to max out the trailer weight. Truck will pull it but stopping will be harder.
I tow a 22 foot Vibe travel trailer with my 2013. It has a tongue weight of 536 lb and weighs 5,200 empty (which it definitely isn't now). I use a weight distribution hitch and have no problems with ride height when I stay close to the cargo limit of truck. The truck has plenty of power to pull and the trailer has brakes. Cooling for the motor and transmission will be your biggest concerns if you plan on going up any steep grades. Feel free to ask more questions.