Notify all members of Organic Group without Message Subscribe

I am a building a website where members of Organic Groups must be notified of the new OG content and comments regardless if they are subscribed to them or not. So in this use case involving "Message Subscribe" module doesn't seem to be necessary and I hope there is a way just to hook into Message Notify's functions to incorporate all the group members' e-mails to the recipient variable, but can't figure out which exact function I need to fiddle with.