Every Microsoft 365 mailbox has a storage limit. When you get close to it, Outlook shows warnings, and if you reach it you may stop being able to send or receive email. This article helps you clear space quickly.
Check how much space you're using
Labels can differ slightly between versions.
- New Outlook for Windows and Outlook on the web: select Settings (the gear icon) > Accounts > Storage. You'll see what's using space, folder by folder.
- Classic Outlook for Windows: select File > Info. A bar under Mailbox Settings shows how much space is free. For a folder-by-folder view, select Tools > Mailbox Cleanup.
Empty Deleted Items and Junk
Deleted emails still count towards your storage until they're emptied.
- Right-click Deleted Items and choose Empty folder.
- Do the same for Junk Email, after checking nothing important is in there.
In the Storage page of new Outlook and Outlook on the web, you can also empty folders or delete older items from a chosen folder.
Once you empty Deleted Items, you only have a limited time to get those emails back. See Recover deleted emails.
Find and remove large emails
A handful of emails with big attachments often use more space than thousands of ordinary ones.
- Go to your Sent Items or Inbox.
- Sort or filter by size. In classic Outlook, select the column heading Size, or search using Larger than. In new Outlook and Outlook on the web, use the filter options, or search for emails with attachments and sort the results.
- For each large email, save any attachment you still need to OneDrive or SharePoint, then delete the email.
Going forward, share files as links from OneDrive or SharePoint instead of attaching them. See SharePoint or OneDrive? for where to save them.
Use your online archive
Depending on your organisation's settings, you may have an In-Place Archive or Online Archive folder in Outlook. It has its own storage separate from your mailbox.
- Drag older emails or whole folders into the archive to free up space in your main mailbox.
- Archived emails stay searchable in Outlook.
- Your organisation may also move older emails there automatically.
The Archive folder inside your mailbox is different: it doesn't free up any space.
If you don't have an online archive, or it's full too, ask your manager to request more storage through the service desk. Changing mailbox or archive size needs an administrator.
Still stuck?
If you've cleared space and still get warnings, or you can't send email, log a ticket or call 1300 079 636.