You wont see "drain tubes" but you should see drain holes. Those holes lead to small tubes that run down the side of the car. You could try using the "stream" setting on your backyard hose to try and force anything that is clogged in there out, but be careful. If you use too much pressure, you run the risk of blowing off the tubes.

Also, continuing to assume it is NOT an aftermarket sunroof, make sure it is properly adjusted via the 6 hexbolts. The sunroof should be 1mm below the roofline in the front and 1mm above the roofline in the back. Make sure to use loctite on the bolts when you retighten them or you will inevitably be doing this adjustment again sometime soon.

Finally, how does the sealing element that runs the perimeter of the sunroof look?

1999 Eclipse GS
Built motor
Hahn 16G Turbo w/ FMIC
Hahn Stage 5 Portfueler (270's & 500's)
Zeitronix Zt-2 wideband w/ 3.5bar MAP
3" SS Turbo Back
CM Stage 4 Clutch and Fidanza Flywheel
Baer Big Brake Kit