Mail and Finder app not quitting.

I have a MacBook Air 13'. trying to shut it down last night did not work, saying finder could not close since a program was running, which nothing was. Later, I tried to send a mail message but it says I have 6 outgoing messages that have already sent and now my mail app will not close, or appear when selected.

Is there any solution to this? I would very much like to have my Mac shut down during the night and while I am at school.