You can easily message your class through a Moodle class page, or through an email request. See more information about requesting these Course Resources.
Old information for lists.carleton.edu (DEPRECATED):
There certainly is! All classes are given a course mailing list when they are created. You, or any students in the class, can send emails to everyone in the course by using the address for that mailing list. These mailing lists follow this format:
firstname.lastname@example.org (department abbreviation, course number, section number, and term)
These lists also keep an archive of all messages sent, which can be accessed on the web at the following address: https://lists.carleton.edu