Greenhouses, Sheds and Sun Rooms - Weep holes?

I've rebuilt a rotted knee wall on a older extruded AL sunroom. I'm now in the process of recaulking. Weep holes are present only on the outside edge/channel of the sill plate but they do not drain the inner channel (which accepts the extruded AL curved eave supports). Water accumulates in this inner channel with no way to leave. How and why? Should I caulk the AL supports where they meet the sill and would this somehow force the water to exit by the weep holes?

Its good that you have even thought of weep holes. You can likely see where the water builds up, where it needs to drain... without a picture of the sill profile I can only guess what it looks like. If you see the need to drill extra weep holes, I'm sure it won't hurt anything, although it might let a few bugs in. Be sure you use 100% silicone when doing any caulking on your aluminum extrusions. And if you can keep water from getting into the sill in the first place, that will help reduce the amount of water that needs to drain out the weep holes.

Just to pass on a hint that I was told, weepholes ought to be oblong- wider than they are tall. Water often will not drain out a round hole due to skin tension.

How is the water getting to the sill plate? I'm guessing that it is entering through the purlins -- the curved AL roof supports. If the roof has the proper pitch, that shouldn't be happening. If the roof is too flat, that could cause the sill plate to be tipped towards the inside of the room. allowing water to collect there, rather than weeping out.