At UAB, the Mail System quota applies to all mail items such as messages, attachments, appointments, tasks, etc., that are in your mailbox on the Exchange Server. It does not apply to any personal folders or archive folders (located on your hard drive as .pst files using Outlook, for example), which can help you keep data you need and stay under your Mail System quota. UAB's standard size limit for faculty and staff mailboxes is 1GB; for students, 100 MB.
This document refers to Outlook mailbox management techniques, but please note that the Mail System quota applies to all members of the UAB community, regardless of what application you use to access your mail.