Any class can use email for collaborative projects with student in other classes.
Email projects are particularly suited for language classes, especially writing classes because the medium of communication is writing. Reading classes can use email for exchanging responses to material read by students in both classes. A least one computer with a modem and a connection to the Internet is needed. Access to a computer network that is connected to the Internet is better. Most universities have computer and many public schools have computer networks that are connected to the Internet.