You can be in a Building code violation.
The building code mandate that the number of room and square footage has something to do with how many people can occupy the house.
In Nevada 2 bed room 1 living room can occupy no more than 5 people (2 per bed room and 1 living room). Anything more than that will be consider illegal. If your house is not large enough, then you can rent them anyway.
Never raise the Money on number of people. unless you listed on the ads.
Also depend on how you word the email, you might place yourself in a weak position.