View your Mailbox Size

The Caltech Office 365 mailbox standard size is 50GB. In order to view your mailbox capacity:

  1. Login at
  2. Click on the settings wheel at the top right of the page
  3. Click Mail, under "Your App Settings"
  4. On the left side menu, click on General, then My Account
  5. Scroll down to view your Mailbox Usage


Reaching your mailbox capacity? 
Click here for instructions to reduce your mailbox size.