Stop spam voicemails with Silence Unknown Callers

Agreed, difficult to do. Voicemail is a carrier service and they are saved on the providers servers. Preventing that from happening will require intervention on their part. Silence Unknown Callers just prevents your phone from ringing, but is not able to stop the carrier from saving the voicemail on their servers.

You want the truth? Bottom line? You can’t. The spammers are keeping ahead of the filter technology.

The problem with blocking one at a time is that the spammers randomize phone numbers to get around the block. Good luck.