What do I do to stop email spam?

How do I stop commercial companies from using MY email address to send spam?

• I continuously receive obvious spam emails that are sent under the auspice of other Yahoo.com users. For example, I will receive an email from [email protected] but the email is obviously not from Joe Smoe as it advertises Rolex watches, Viagra, Medicare, or other spam trash offers. I even receive emails TO me that are FROM MY OWN yahoo email address! Some company / companies appear(s) to be pirating mine and other people's Yahoo.com email addresses to broadcast spam commercial emails. I thought maybe my password had been compromised, so I changed it to another statistically very secure password, but that had no effect. How do I stop these buggers from exploiting my address?!?!

• Answer:

  Check the sent folder to make sure its from your mail. If so change your pass word.