Question [Q] Receiving Voice Mail Notifications for BOTH numbers on a Dual Sim Card Phone.

I have an HTC ONE E8 Dual Sim Card Phone. Basically the same as the M8, but w/two sims. One line I use with data as my personal phone. I am able to receive voice mail notifications on this line, but for my second line (business) which I have no data plan, I have not figured out how to receive voice mail notifications which is a bad thing because unless I call my voice mail manually, I am losing business. Can anyone help?