Check to see if telephone number is active/real [closed]
Closed. This question is off-topic . It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 7 years ago . I have a new project on hand on which is quite complex as i am not aware of its domain. My requirement is this, We have list of telephone numbers and from this list i need to check which telephone number is active/real. How would you program a telephony or IVR system to automatically dial phone numbers on this list and automatically detect if it is a valid phone number or not? I would like to use C# to program