I have a computer for while and it worked just fine. Since last week, I cannot defend from some chain mail spam. I do not know how they find me. Every new day I have more and more spammers attacking me. I almost cannot use my email client, anymore. How to deal with and avoid chain mail spam? I've heard that some professional sites use chain letters, like FaceBook. Why?
If you do not want to get sick, you have to practice personal hygiene. It is almost the same in cyberspace. If you do not want to infect you should respect few basic rules of online hygiene. First, never register your main mail address on any email list. If that list is spamming list, it will trade your address to other spammers and you will find in the situation like yours now. The other thing is to avoid opening any mail from unknown user or with "best offer you can get". Chain letters are efficient weapon for direct marketing and that is why some serious site uses them. They are not doing direct damage to your PC except spamming your email. Because you are already infected, we will have to find the cure for your illness. I could personally recommend you the program Mailwasher. That program intercept your emails and delete the spam for you, therefore you do not need to deal with it.