I am planning an event and would like to use the gym space at a local elementary school. how do i send my prop?

I would not use email for something that can be done in person. For a event type of the nature you are wanting to organize, I would simply start with the principal at your local elementary school. He/she can then direct you to the person or persons you may need to contact further. Simply call the school you have in mind and set up an appointment to speak with the prinicipal. When doing events for the Girl Scouts, we simply went to the school prinicipal to get permission to use the gym facilities. You do need to sit down and make a list of questions that you may have like, what dates and times are better than others, what precautions need to be taken for the gym floor( a lot of gyms are now treated differently than back when you could only wear white sneakers), ask if they can supply tables and chairs, a lot of times they dont mind and some may even have a cafeteria area better suited for this type of event, or even hallways sometimes. Of course each city has its rules concerning garage sales so be sure you know what those rules are and you can contact your City Hall to find out those answers. You also need to decide where all the proceeds of the sales go to, will they go to individuals that participate or to a local charity, maybe even suggest a percentage go to the school you will be using for janitorial services and so on. Good luck and hope your event turns out to be a success