Hi Sekiro,
It should be possible to achieve this by parsing the call events. You could set up an application that continues to try to call until an Answered Call Event (ACE) was received, which only occurs after a call is answered. If the number you're calling is using an answering machine/voice mail, the voice mail answering the call counts as an ACE, but for that we also have Answering Machine Detection (AMD), and so you could further parse whether or not the call was answered by a human or a machine, and then keep trying the call until a human answers.
It's not exactly the use-case you're asking for here, but you can view this tutorial to see an example of using ACE and AMD together to check if a call is answered.
Let me know if you have any other questions, and I'll try to help.
Thanks,
Alex Sberna, Documentation Engineer
