I did have the same problem a few months ago. I was away for 2 weeks ( and didn't used the internet as I wanted a fortnight of complete relaxation....). When I came back I found over 80 of such gibberish messages. Worse was that my friends and family e-mailed me to ask me what message I was tried to e-mail to them....Some were from Africa, Hong Konk, and Argentina.. It took me ages to get rid of them ; then the computer was slow to start and crashed regularly. Sometimes I couln't log in as the message came that username and /or password were incorrect.....I finally got a local whiz-kid ( well, he is in his 40s.....) to come and clean it up.......it took him 3 hours.....I am OK for the moment ( should I really say that.......I could jinx it...) ....I still don't know what happened.....