I am looking for a service provider that will allow me to transfer calls to voicemail. Then I can use an API of there's (in PHP preferably) to access the voicemail and any metadata and then do with it what I like such as generating emails, tapping into a transcription service, etc...
I know that http://www.ribbit.com/ is new and looks like it might have some of what I need, however, I would also need a number to dial in to leave the message.
The company I am working for is developing a virtual receptionist that will allow them to forward calls to voicemail, so I would need a way to forward to a specific voicemail box for a specific customer.
Any suggestions, or does something like this not (yet) exist?
Take a look at Tropo. It seems to have much of the functionality you describe, and a few more which will tickle you pink - including SMS service. It's also free for development and cheap for production.
I don't work for Tropo or affiliates, i just have heard good things about the service.