Yes, individual email users can see their email storage usage in the webmail interface. Here are instructions on how to view your disk space usage:
1. Log in to the SmarterMail interface (http://webmail.yourdomain.com).
2. Once in the SmarterMail interface, click on the "Reports" icon on the left hand side (it is an icon that looks like
a bar graph).
3. Click to expand the "My Reports" folder.
4. Click "Disk Usage"