Welcome to Android Forums, Ozdingo!
It probably has nothing to do with the tablet per se. You are sending email out over your network and depending on your provider they may require some for of authentication to do that. I know having a Verizon dsl line at home i must not only authenticate all outgoing mail, but i must use a non-standard port. Check your outgoing settings with your provider to see if you have to use anything out of the ordinary.