There are visual voicemail app that can do that. Search the App Store and you’ll fine them.
I don’t know if it’s true but I could believe it because visual voice mail services take over the voicemail your carrier normally provides, and part of this might be screening incoming numbers (eg send some numbers straight to voicemail). It wouldn’t be the app doing it per se (it would be the remote service you merely manage via the app) but you get the (theoretical) idea.Unless you can point to some, I don't think there is. As far as I know, without jailbreaking or your carrier doing it, there is no way to block unknown or blocked caller id numbers.
I don’t know if it’s true but I could believe it because visual voice mail services take over the voicemail your carrier normally provides, and part of this might be screening incoming numbers (eg send some numbers straight to voicemail). It wouldn’t be the app doing it per se (it would be the remote service you merely manage via the app) but you get the (theoretical) idea.
not necessarily because it’s possible for you to forward all calls straight to voicemail if you choose - that’s a standard voicemail feature. By extension it’s conceivable you can forward certain numbers to voicemail, and by further extension conceivable you can forward them and block them leaving voicemail. The call never reaches you.I think what the OP is looking for (and I wouldn't mind as well) is for the phone to not ring at all if the caller id is blocked or unknown. Having a third party visual voice mail wouldn't stop those calls. It would just handle what happens after the phone rings, goes unanswered and then is forwarded to VVM.