I am getting buried in these as well, and I too initially wondered why something so blantantly obvious as Approved Viagra Store or similar passed the spam filters on a consistent basis!
AND THE ANSWER IS ... While it LOOKS like that is where it is coming from (the name) if you hover over it, I'll bet you'll find that the actual address it is coming from is YOURS !!
Apparently with Thunderbird at least, it looks at the senders address and not the senders NAME. I solved most of this by setting up a filter that puts all email sent by me into the junk mail folder. This actually worked extremely well as I rarely send myself mail. However I am just now running into a problem having set up email forwarding from one of my domain names. I can't get it to look at the email NAME rather than the address. -Sigh- So while I may have addressed YOUR problem, I wish I could fix MINE!