Just tried this. After a few rings you get a default message where some guy says "The person you have called is unavailable right now, please try again later."

We could actually set up some fancy forwarding to make this message configurable, similar to how Google Voice's voicemail works.

I'm thinking the reason you can't get the feature you want is because some engineers who designed the call setup for cell networks decided keeping the phone's battery from dying as a result of excessive ringing is a nice feature. I'm with you though, I hate voice mail. So does my mom. She recorded her outgoing message to politely say she never checks v/m and to text or email.

Sony Z3's have voicemail built in. Sadly they are glass both sides and break too easily. The other thing to consider is that when you are out of range or it is turned off, you may well miss an important call. All smartphones should be able to take a message first, and if that fails, then, it should fall to the carrier.

The caller can still text you or email you.

Which would be fine with me, since the scammers/spammers wouldn't do it. I don't like voice mail; but there is a difference between voice mail from a friend or family member and one telling me I've one a free carpet cleaning, an alarm service, need new windows, etc. (Not to mention the upcoming political robocalls.)