Reducing Mailbox Size

Office 365 mailboxes have a standard 50GB capacity. To keep your mailbox size below this limit, first login in to Outlook web via Then follow these recommendations to reduce your Office 365 Exchange mailbox size:


Empty your deleted items

  1. In the folder structure navigate to the Deleted Items
  2. Right-click on the Deleted Items and select, Delete all


Empty the Recover Deleted Items

  1. In the folder structure navigate to the Deleted Items
  2. Click on the link for Recover deleted items

  3. A new window will open, select all messages and click Purge


Sort email by size and delete large messages:

  1. Navigate to the Inbox, click on Filter and select Sort by > Size

  2. The largest items will now appear on top
  3. Download large attachments
  4. If desired, delete message


Other useful links: