Mailing Lists In Mac Mail

How do I stop a hijacker sending junk e-mails in my name?
I opened my e-mail and found an explosion of messages from people saying they have received a junk e-mail from me. Turns out, something has hijacked my entire e-mail contact list. It has sent the same message twice…so how do I get rid of it? I’m on a Mac (OSX 10.4.9) and have never had a virus before. Is there a good program for this?
I’ve had this account for years and don’t want to delete everything in it.
What’s a good anti-virus program for this?
Steps to follow:
1. Change your password. Set a difficult one like: Tgdi52^drO*@!gd6
Write it down and memorize it. Make sure you don’t loose or forget it
2. If you use a program like Outlook then stop using it. Remove all the settings leading to accesing your account
3. Do full virus scan
4. Use a browser to access your email
When choosing a password check it at Password Checker from Microsoft
http://www.microsoft.com/protect/yourself/password/checker.mspx
Choose a “best” password.
(Changing your password and making a virus scan is very important)
Success