Weird emails showing up in my inbox

Hello! My problem is that I’m all of a sudden getting lots of email bounces for email messages that I never sent. The bounces show that someone claiming to be me, or at least, is sending spam about replica watches or some crap like that, to various random people, including Yahoogroups. I go offline for one day and this is what happens as soon as my back is turned! What or who is causing this and how can I make it stop? Thank you very much in advance for any assistance, as I am baffled and appalled.

I dub thee Joe:

Short version, you can’t stop this.


Thanks for the link.