For NGOs: You are an active NGO; you have a project idea. It would be great if you could reach out to those in the festival scene. You write an email to the festival aaaand you get an automated response directing you to a ticket sales website... OR NOT?
It is important to contact the right people in a festival organization for possible cooperation. As you can imagine, a festival can be a massive organization with many people with many different responsibilities. If you reach the security or food & beverage people; even if they would like to help, or they are interested, things can get lost.
Make sure you identify and contact the "right" people: Is there a sustainability manager? A communication manager? Social responsibility officer?
In short: Don't try to contact the owner or director of the festival, because you read about her or him in the news, if you want to get in touch with a certain department.
If you can't find a contact person online, and your email to the official email address doesn't get a response, don't hesitate to pick up the phone. Call the official phone number and ask until you get an answer.
For festivals: You have this brilliant idea to open up your festival space this year, and you wish there were some NGOs dealing with your area of interest (e.g., environment; equality, fight against racism; social cohesion, etc.) present in the festival. Wonderful. Do your homework! Maybe this is too much to ask from a student club or the tiny youth center in your neighborhood.
NGOs move in specific circles that do not necessarily overlap with festival circles and are often local (international or national NGOs usually have city or country groups). You can try to find out on which platforms NGOs connect to each other and promote your festival there, while explaining participation requirements, application start, etc. It may be a good idea to check with umbrella organizations such as the national / regional youth councils; federations and city youth parliaments.