Once you block a phone number, that number will not be able to reach you. The moment it tries to do so, voicemail will immediately be activated for it, and you will never receive a notification that the person wanted to contact you. As for messages, when a blocked number sends you a text message, you will never receive it and the blocked person’s phone will show that his message was only sent. There are two simple and similar ways to block a number. If you want to block a contact that neither is in your contacts list nor has contacted you recently, you must first add this number to your contacts list.