[fetchmail] Is access.db the only answer.

I've been getting emails addressed to my domain for people who don't exist 
here. My guess is people are mistaking Solution Design Laboratory with
San Diego Library. 

I have three email names that are legitimate but anything else should 
bounce. I'm not sure what the proper search subject would be to determine
the answer to: "How do I reject emails to users which don't exist in my 
domain?"

I have had my emails bounce when the recipient no longer exists. How do
I set that up on my own system?

Or at the very least, what is the proper search subject I need to find?