You ARE aware I hope that you have posted your actual name, if this IS your actual name, in your thread on a public, open forum. I have edited your post and removed it.
You say in your post
"(I always use my Orignal name "xxxxxx" while Subscribing newsletters or giving comments)". This means you are putting your name out there for the World to see. Do a google search for this and you will receive thousands of links bearing this name.
It is very likely that somebody has hacked your account or hacked your computer entirely.
If it is a webmail only, accessed via the browser, then it is probable the account itself was hacked. Email Hackers have only one job, hack email accounts in order to do exactly as they have done with yours in order to spread their malicious programs, files, websites to others. They are very patient and can sit for days trying various letter and number combinations until they get a "hit" of a legitimate account name, once they do that then they work on hacking the password in much the same way. Once they have both then it is "game on". "Professional" hackers don't do this manually, they use specific programs to do this for them.
If this email was sent through an email PROGRAM installed on the computer then your computer itself has been hacked and hijacked and you should most definitely follow all the steps given in our Read Me Sticky
http://www.daniweb.com/hardware-and-software/microsoft-windows/viruses-spyware-and-other-nasties/threads/134865
and post right back here with all the requested logs.
You may have been lucky since the infected mail was also sent back to you and your AV program caught it, it's likely there were some other people on your contact list were not so lucky. Not everyone takes proper security precautions, plus remember too, others, seeing the email was from you and they know you then they very likely may have opened the mail and infected their computers.
