I get voicemails on all my phones but the message waiting light never comes on. This is real difficult because you have to constantly be checking to see if you have any voicemails. Where is the setting to turn this on? I would give you versions of what I have but I am not sure where to get this?

What mail do you have?, should be something on it like Imagen or something, you need to look at the Set Message Light and make sure it is set to yes in the mailbox parameters.
Need to know if it's Imagen or Emagen or evn a third party.

It is Emagen.

I looked for the Set Message Light but it is nowhere to be found.

In mailbox properties there's a setting for MWI make sure it's set to A for all, for that mailbox.

Also in your programing of the system, make sure you have a MG button on the map.

well at least we found out what mail ya got, the newer one, that's good, I would assume you have avanti sets as well, on those I usually put VCML on the button.Assuming that's what you have.