While your custom and transactional emails will come from a @courses.maven.com account, if students reply to the email, they'll be sending the email to your reply-to address.

In your Course Settings, there's a field where you can enter your reply-to email address.

Usually, Maven instructors set up a custom email address on a domain they own. Some create something as simple as a @gmail.com account where they manage all their course correspondence with students.