I will chime in and say what others have said, be VERY careful. Searches don't bring up anything on either the e-mail you gave or "Travel Getaways Inc." and it is most definitely NOT from the postcards we all have been mailing in. They don't ask for our e-mails on the postcards and they show in the rules that contact will be made by mail or phone. Someone mentioned a possible time share, it could be, as they seem to do this often.
Do you enter other sweepstakes? did you enter to win a trip such as this?
Because these scams happen often, so again, I am not saying they are not legit but saying be very careful. The second they ask you for any info. concerning money/banking/credit card info. you will know for sure it is not a sweepstakes win.