I keep getting spam calls from a number every night at midnight. I've blocked it, but now it just goes to voicemail and I have to delete the voice messages every morning. It's annoying. Is there an option to block it from leaving voice messages, or just automatically answer then hang up? I haven't found one in Android itself (my phone has ICS).
I've also tried Mr. Number, which I thought would do this, but it doesn't. It does work, see update below. I've also talked to my carrier about it, but apparently I'd have to add "smart number blocking" or something to my plan for about $5 a month. If possible, I'd rather just get an app answer & hang up than have another fee to pay.
Delayed Update: I followed the directions eldarerathis provided below for Mr. Number and it does what I was trying to do; I must have just done something wrong before. The phone will still ring for a few seconds though, so it may be best to silence it if the call comes at a consistent, inconvenient time like it does for me.
Not for Ice Cream Sandwich, but in Marshmallow, the stock call blocking also deletes voicemail.
Calls from these numbers will be blocked and voicemails will be automatically deleted.
The free App call control works pretty good. You can have a number blocked and set up so it picks it up and hangs up. It doesn't let them leave a message and your phone don't ring. However If you go where you don't have service it will still send it to voicemail, but works great otherwise.