Draft a short letter, specifying the name of your organization, contact information, purpose of showing a movie and other relevant information. Printing the letter on your organization's letterhead stationery could also be helpful.
Contact the Motion Picture Association of America's piracy department, at [email protected]. The MPAA answers responses to questions about fair use. It can also provide an updated copy of the "fair uses" guidelines.
Look up the distributor of the film at Internet Movie Database. The film distributor is often distinct from the studio or producer. Contact the distributor to discuss your intention to show the film.