Just don't do it.
Chain letters, my friends, are evil. They are filled with lies and idiocy and sometimes, they strike a chord of fear within us and we think: "It might be true!" and then we forward it on, to our unsuspecting friends and family members.
Let me be the one to tell you, if no one ever has before, that there's a service out there that can help you: Snopes.com.
They'll tell you all about the latest and greatest of Urban Legends and bizarre email chains that are going around. They'll tell you all about the Nigerian and how that man is never ever going to send you money and how your momma won't be killed if you don't forward on this email message. You won't ever get money out of Microsoft for forwarding on that email, that "stolen" recipe for cookies isn't real, and your friends will have neither good nor bad luck if they don't forward on that trite poem.
What you will do is clutter up your inbox and that of your friends and family members, at the very least. At the worst, you'll have accepted viruses or worms, given personal info to spammers or managed to corrupt your system. Does your computer seem to run slower and slower, even though you've never installed anything new on it? You probably have spyware all over it. Get help. Download free spyware removal programs. Run it every month. Or every week if you can't help but accept cookies from every web site you visit.
So, please! Please! Pretty please!
Don't forward on emails that contain messages that are too good to be true, too frightening to be real or threaten or cajole you to "not break the chain".
If you're not certain of the info contained in an email, look it up on snopes.com first.
Just keep in mind: chain letters are evil. Think of them as infectious germs. Don't pass them on.