Just so, how do I stop blocked numbers from leaving voicemail?
Android has built-in call blocking, similar to iOS. Just tap a number in your call log and hit Block/report spam. And like Apple, this method has the two same drawbacks. Android also has the option in the Phone app settings to automatically identify and block suspected spam calls so they don't ring your device.
One may also ask, why can a blocked number leave a voicemail? Block a Number from leaving your a Voicemail in Android
It has a feature named 'treat as spam' which prompts the blocked number to leave a voicemail but the voicemail is automatically marked as spam in the inbox and you don't get any notification for that voicemail. It's a paid app ($4.99) on Google Playstore.
Also to know, can I listen to a voicemail from a blocked number?
The short answer is YES. Voicemails from an iOS blocked contact are accessible. This means that blocked number may still leave you a voicemail but you will not know they called or that there is a voice message. Note only mobile and cellular carriers are able to provide you with true call blocking.
Can you see if a blocked number has tried to contact you?
If you have a smartphone Android, for know if a blocked number called you, you can use the call and SMS blocking tool, as long as it is present on your device. After that, press the card call, where you can see the history of calls received but blocked by phone numbers that you previously added to the blacklist.