Outlook on the web
- Log into Outlook on the web
- Click the gear icon > Mail > General
- Click My account.
- Within the "My account" screen, view your mailbox quota located at the bottom right of the screen.
Outlook 2016 for Windows
Note: These steps assume you are connected to your Office 365 account via Exchange. By default, this feature is turned off.
- Start Outlook.
- Right-click anywhere on the bottom Outlook bar.
- Click on the first option "Quota Information" and you will see that it switches to the "On" mode.
- You can now see the amount of free space left and the number of items you have in each folder, in the bottom left hand corner of the Outlook bar.