Ringless Voicemail Software

We're looking for a simple software to run our ringless voicemail campaigns. This will not be used for public only for internal. The use of a dnc list would be nice. Usual setup with dialing twice and then leaving our audio file message. On completion a report if it's possible of the success of the campaign. We use CSV spreadsheets for the contact data. Doesn't need to be fancy just effective. Possible use of Twilio unless you have a better suggestion. This software is to be developed for Windows unless a better platform can be used.