Yes, one of the byproducts of the engine's combustion process (i.e. burning fuel) is the production of water. It is not uncommon to see water drip from the muffler or the tailpipe, especially when the vehicle is first started and the exhaust system is not at full operating temperature. If you ever see a constant flow of water (or worse antifreeze or oil) that is not normal and could be a sign of serious engine damage.