Why do I keep getting emails in my bulk box and spam emails with a differen email address to mine?

I recieve lots of emails that are not addressed to me.Especially scams from Nigeria and bank scams. Surely these can be filtered out one would think.

Why do I keep getting emails in my bulk box and spam emails with a differen email address to mine?
1. sometimes spammers simply make up emails and send them out, like johnsmith@aol.com,johnlee@aol.com, etc.





2. if it's in your inbox and you're not in the TO: or CC:, then you're email is in the BCC: field





3. use a different email address when signing up for things on the web.