Depends on the GVWR of your trailer and what else you are going to pack into it.
For example:
If you have a 3500lb capacity and the trailer itself weighs 800lbs empty, you could load your 1200 lb smoker and have 1500 lbs max cargo carrying ability. Of course that is assuming you have properly sized tires in good shape.
My advice is to keep your load well under the max rating, especially with a single axle trailer. With only one tire to the side, a blowout on the trailer at highway speed can flip your entire rig! Mightly ugly stuff, and trailer tire failures are fairly common with heavy loads.