What you have isn't a proper drain line in diameter, material, or slope. Unless you're willing to tolerate the slow flow and clogging from time-to-time, hire a plumber to replace it with PVC following your city's plumbing code.

+1, Dan. I thought the same thing.

I researched how to properly run such a drain line and it did not take long to come to the conclusion that a five gallon waste tank under the machine would be the best solution for me, at least for now. In comparison, running a water line is simple compared to drain lines.

I would use a combination of plastic pipe and flex tubing with the plastic pipe making up the great majority of the run. LM specs out a 5/8" drain hose (presumably 5/8" ID).

Slope the plastic pipe 1/4" per foot.
Use flex tubing to go from the machine to the beginning of this ~8' run of plastic pipe.
Connect the tubing to the pipe using a "Y" with cleanout port (this Y you may need to make).

I use to work construction between semesters in college. Let me pass on some words of wisdom that an old master plumber told me one summer. "Son, plumbing isn't hard. You only have to remember 3 things. Left is always hot, right is always cold, and sh** don't flow up hill." I would guess the angle of the dangle is not correct. You may want to use some nylon zip strips with a screw eyelet and tie up that line. Keep it nice and taunt and sloping down from the machine to under sink hookup. Having said that, draining my A3 out was more hassle than I wanted to mess with so I have not drained out a machine. I had no close by drain but the house mains was close by so plumbing in the bar was not an issue. I just drain to a 3 gallon bucket that sits in the cabinet and empty it twice a week.