Yesterday a guy knocked on our door and asked to speak to 2 people who no longer live here and was told that they haven't in over a year. He left 2 envelopes here for those people .There is no return to sender address on envelope, just hand written. What is my role in this under Australian Law? Do I open it up and find out who to send it back to ? Or do I throw it out ? I have no forwarding address and don't believe it is my role to find out and send it on. They placed it in my door frame and said they were leaving it here and what it is about and turned around and left.