Is there a way to archive all emails sent and received by every account on a single domain and store them on a different, less expensive server than the one being used for email hosting?
Yes, you can use email archiving or just create a backup of the accounts to do this.
The documentation on archiving can be found here: Archive | cPanel & WHM Documentation and more specifically for what you'd like is: Download Archives | cPanel & WHM Documentation
The documentation on archiving can be found here: Archive | cPanel & WHM Documentation and more specifically for what you'd like is: Download Archives | cPanel & WHM Documentation
