Penpals to Exchange students?

I am looking for an opportunity for my students who are in their third or fourth year of French to communicate by letter with students in France. I would love to also collaborate with their penpal’s teacher on projects. An ideal situation would lead to an exchange.
My program is new and small. I will have around 20-25 students next year for French 3 and about 10-15 students in French 4AP.