hi, you dont mention the content of the emails or the header lines they are being bombarded with. If its porn you may have some virus.
Try sweeping your computer with your latest virus protection. If you dont have an antivirus program then AVG do a really good free one.
AS a general rule, dont ever open emails unless you are reasonably confident of their content. Its easier to apologise for deleting your friends messages than it is to remove a vicious virus.
Do you have a firewall? Zonealarm is the best freebie.
Also use Lavasoft adaware, Spybot, and Spywareblaster to remove any spyware.
Update regularly and sweep regularly.
hope you dont lose too many friends to mad emailing!
jc, August 2007