Faculty, staff, and alumni: 2.5 GB total.
Students: 2.5 GB for email and 2.5 GB for home directory files.
If you approach the email quota (80-90% use), you will be sent a warning message. Once you hit the quota you will no longer receive any email (except warnings about your quota); people who send you email will be sent a message informing them that you did not receive the message.
Log in to webmail to see your quota and usage at the bottom-left of the page. Hover your cursor over the pie icon and % used.
Use HampNet Account Management to check your quota.