I replaced my broken S3 with another used one and since then, 2 of my friends can't text me. They get a "failed" message when they text me. I can text them, and I am receiving texts from my other contacts. I checked to see if my phone was set to block messages are it isn't.
AFAIK, the sent/failed message is simply a confirmation that the text message has been successfully handed off to the network by the sender's phone. It should have nothing to do with whether your phone is able to receive the message. Text messages blocked by the intended recipient typically just disappear into the ether.