Globaliser is probably correct about the source of the unwanted emails.
As for a solution to the problem, it can depend on your email program. One solution is to set up a rule that runs when you run your email. It will search the server for the parrameters you specify, like message headers that contain a phrase " Undelivered mail" , if its there delete it from the server. that way its gone before you see it.
Of course you could change your email address perhaps.