Mail problems

I have had some problems setting up my mail. Finally I think I have it solved, however, when I open Mail on the left hand column under time machine I have two recovered mailboxes and two recovered messages. One of the mailboxes has 300 emails that were from my previous and unsuccessful attempt to set up mail. How do I get rid of these, and before I do, how do I get those recovered emails back in my mail box? Sorry to be so confusing, as I am still learning.

I solved it. I chose the recovered mailbox with the three hundred emails and then highlighted them and dragged them into my present inbox. Then I highlighted each of the mail boxes and each recovered messages and and went to the Mailbox at the top and chose delete mailbox and now they are gone.