James said:
no it is not from or to the actual user
Without seeing one, I can only guess, but my guess is that your address has
been hijacked and is being used one some other computer by a spammer. The
spammer is sending messages with your address as the sender address and some
of those messages are bouncing. Since your address is the sender address,
the non-delivery reports are being sent to you.
Post one of the messages, being sure to mask any real address in it, but
leave the rest intact.