Outlook says Microsoft storage is full although storage shows only 62% used

JónGrétar KJARTANSSON 0 Reputation points
2026-10-13T08:06:33.6266667+00:00

I have a Microsoft 365 Family subscription.

My Microsoft storage page shows:

  • 732.4 GB used out of 1.2 TB (62%)
  • Email storage 28.8 GB used out of 100 GB (28%)

However Outlook still displays:

"Your Microsoft storage is full. To send messages, you'll need to free up space or get more storage."

I am unable to send emails.

I also tried to contact Microsoft Support, but Support Assistant fails with:

"Chat stream request failed: 500 - Request headers must contain only ASCII characters."

Has anyone seen this problem before and how can I get Microsoft to refresh or repair the storage quota on my account?

Outlook | Windows | New Outlook for Windows | For home
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  1. Lychee-Ng 29,315 Reputation points Microsoft External Staff Moderator
    2026-10-13T12:42:33.99+00:00

    I understand how frustrating this is, JónGrétar KJARTANSSON.

    And you don't seem to be the only person who has encountered this, as I've encountered similar threads before. In those cases, Outlook/OneDrive often report a storage mismatch, where the service treated storage as full even though it's not. The recommended workaround for those cases was:

    1. Sign in to https://outlook.live.com/ > empty the Deleted Items folder.
    2. Look for and delete the emails larger than 10 MB (containing attachments)
    3. Sign out of Outlook completely > restart your PC > sign back into Outlook web.
    4. Check whether the storage information updates and try sending a test email.
    5. The changes can take up to 24 hours to apply, so wait a bit if needed.
    6. If it works again, restore the deleted messages from Deleted Items.

    Unfortunately, if the workaround does not help, this likely requires Microsoft Support to examine the account’s server-side quota. Microsoft Q&A is just a user-to-user forum, so we cannot access the account or manually refresh the storage quota from here. Because Support Assistant is giving you error, try the following tips:

    • Open the support request in an InPrivate or Incognito browser window.
    • Temporarily change the page to another language (E.g. English <> Icelandic)
    • Sign in with your account at Contact Us - Microsoft Support   
      • Enter / choose an issue > click Get Help to make a request     
      • Scroll down > click Ask our Support Assistant and follow guidance   
      • If the issue persists, specifically state in the chat box that you need direct help.   
      • The Contact Support button should appear > click it > select the chat in browser option. 

    User's image

    User's image

    Note: The support contact team only works at certain times, so if the last window shows that it's unavailable, try opening it again the next day. If you prefer phone support, you can leave a phone number. This way, they can call you and help you. If you don't see chat option, choose another category and ask to escalate. 

    Tell Support that Outlook appears to have a Microsoft storage mismatch and ask them to check or refresh the quota assigned to the account. This should help prevent the case from being handled as an ordinary full-mailbox problem.

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