When i open my e mail it says undeliverd mail that i did not send?

i get lots of undeliverd mail not sent messages

these messages our sent even when my pc is off i have changed my passwords and never hold them in memory i run up to date avg anti virus and run anti spy adware daily if not weekly

these messages are not being sent by me?

When i open my e mail it says undeliverd mail that i did not send?antivirus scan

Someone is faking your email address on spam they're mailing out. This is a common practice. They're hoping that by using a real email address, other people will read the mail instead of just throwing it away.

Write your congressman. Ask them to make this practice illegal. Ask them to shut down any ISPs that pass illegal web traffic.