mirek03 > 'some of those you and Steve referred to, one has to wonder do they really fool people or is it a probe for the address??'
I think the mail servers record wether a email you sent was delivered or not. I just blocked a few IPs and the spam now comes from a different address since my ISP automatically sends a 'message undelivered' reply back to the originator.
C. P. U. Its not a big processor... Its a series of pipes!