There is currently no way to mass message all your followers within Deepbot and honestly, I doubt there ever will be. Considering you want to send a message to all your followers, however big that might be, the message being sent in that fashion might possibly be considering in the same fashion as the bot viewing messages that you could occasionally get.
That's not to say these kind of things don't exist. You could probably use the Twitch API to pull a list of your current followers then with that information send a PM but I haven't delved into the API enough to give you a concrete answer.
In short, this kind of mass messaging would probably be considered as spam and would more then likely currently be placed in the "other" folder, rendering your mass message mostly useless.
Sorry,
Dante557
