People, you only get to cast one vote. If you receive a mail in ballot, that is a ballot and that is yours. You can mail it in or drop it off at an early polling place (or where ever the instructions tell you to).
If you change your mind about voting by mail and want the thrill and excitement of voting at a polling place, you will be given a provisional ballot. That ballot has to be hand checked to ensure that you didn't cast the mail in ballot you requested. So don't be mad or disappointed - your vote will still be counted.
I'm curious to see how all the provisional ballots will affect the timing of the election results in this remarkable election year.