Boneprone read this man:
"Because this worm does use a randomly chosen address that it finds on an infected computer as the "From:" address, numerous cases have been reported in which users of uninfected computers receive complaints that they have sent an infected message to someone else.
For example, Linda Anderson is using a computer that is infected with W32.Klez.E@mm; Linda is not using a antivirus program or does not have current virus definitions. When W32.Klez.E@mm performs its emailing routine, it finds the email address of Harold Logan. It inserts Harold's email address into the "From:" line of an infected email that it then sends to Janet Bishop. Janet then contacts Harold and complains that he sent her infected email, but when Harold scans his computer, Norton AntiVirus does not find anything--as would be expected--because his computer is not infected.
If you are using a current version of Norton AntiVirus, have the most recent virus definitions, and a full system scan with Norton AntiVirus set to scan all files does not find anything, you can be confident that your computer is not infected with this worm.
There have been several reports that, in some cases, if you receive a message that the virus has sent using its own SMTP engine, the message appears to be a "postmaster bounce message" from your own domain. For example, if your email address is
[email protected], you could receive a message that appears to be from
[email protected], indicating that you attempted to send email and the attempt failed. If this is the false message that is sent by the virus, the attachment includes the virus itself. Of course, such attachments should not be opened"
Read more here:
http://[email protected]