To reduce your Outlook data size and avoid performance issues, it’s important to regularly delete unnecessary emails and monitor your mailbox usage. Deleted emails are moved to the Deleted Items folder, which must be emptied to fully free up space.

🧭 Steps to Check Outlook Storage Usage

1. Open Outlook
2. Right-click your email account name in the upper-left panel
3. Select Data File Properties
4. Click Folder Size in the lower-left corner of the window
5. Review the total size, individual folder sizes, and inbox capacity

🧹 Tips for Reducing Storage

• Delete old or large emails, especially those with attachments
• Empty the Deleted Items folder after deletion
• Archive older emails to a separate PST file if needed
• Be aware that some deleted emails may remain on the email server and be re-downloaded unless server-side deletion is configured

📌 Note

If deleting emails doesn’t reduce your local storage, contact your email server administrator to confirm retention policies or server sync settings.