The fact of spammers using your email address to spoof their identity has nothing at all to do with which brand of computer you use. They get the addresses from the internet, either by using bot programs to scan web pages and Usenet groups for them, or by simply generating random address strings until they hit on one that works. It's the same when they send email. They use programs to generate random user names and then tag them in front of domain names they've harvested or learned from lists other spammers have collected. The idea that macs are somehow immune to problems that affect PCs is purely an advertising ploy on the part of Apple. Apple certainly cannot guarantee that you will not receive spam, or stop spammers from sending mail to or spoofing addresses from one of their internet mail servers.