03-30-2012 09:27:10 PM
Sorry this was previously addressed by an AT&T Specialist, but it was done so well I am copying it for you. It actually is posted 2 inquiries below yours.
If the person who is trying to text you is an AT&T customer, they would receive a text message that says: The wireless subscriber you are trying to reach is not accepting incoming msgs at this time.
If they are not an AT&T customer, they would not get a message back and they would not know whether or not their message was successful.