Glows are post rendering, i.e they are added after the scene is rendered to the objects, this might be why it dosent work, as you said Maya would just consider the object to be solid and therefore as you cant see through it it wont apply the glow.

If It was me I would just use a light instead along with the model of the sun you have, that way the light will shine through the objects and act more like what sunlight would do.

That is if I understand your problem