We understand it's important to know if your message went through, iphonecurious. When our customers subscribe to Message Block (www.vzw.com/spamcontrols), the sender receives a text reply stating: "VZW FREE MSG: You cannot send messages to the destination that are blocked by the owner." I would not be able to confirm if there's a message sent back to the sender if the customer happens to be using a different setting or application to block messages though.
Follow us on Twitter @VZWSupport If my response answered your question please click the �Correct Answer� button under my response. This ensures others can benefit from our conversation. Thanks in advance for your help with this!!