Cannot send emails due to Out of storage error even after i have purchased M365 Family subscription

Question

Cannot send emails due to Out of storage error even after i have purchased M365 Family subscription.

I have utilized 344 gb out of 1tb for onedrive and 12gb of out 100 gb for emails. Still i get out of storage error and cannot send emails. any action items i can implement to fix this?

Answer 1

Hi!

Welcome to Microsoft Q&A forum.

This is a very confusing issue with Microsoft 365, your storage numbers look fine, but Outlook says “out of storage.” This normally indicates that your mailbox and subscription are not syncing correctly. Let's check it properly to avoid confusion.

First, you must confirm your mailbox actually has 100GB by going to Outlook Web (outlook.live.com), click settings(the gear icon) then go to General > Storage. You will see here If it shows 15GB limit or not.

Next, check your subscription is tied to the same account by going to Microsoft Account (account.microsoft.com). Once logged in you will see if Microsoft365 is active and if this is the same email you use in Outlook.

Once checked let me know so I can assist you further.

Answer 2

The error occurs because the Microsoft cloud storage quota is exceeded, not just the Outlook mailbox quota. Even if the Outlook mailbox shows plenty of free space, hitting the unified Microsoft storage limit blocks sending and receiving email.

Key points from the storage system:

• If Microsoft cloud storage is exceeded:
  • Cannot send or receive email in Outlook.com, even if email storage is not full.
  • Cannot upload, edit, or sync new files to OneDrive; existing files become read‑only.
  • Cannot send or receive Microsoft Teams messages with attachments.
• If only email storage is exceeded, email is also blocked.

Action items to fix the issue:

1. Confirm which quota is exceeded
   • Check both:
     • Microsoft cloud storage (OneDrive + other services)
     • Outlook email storage
   • Use the “manage storage” and “mailbox storage” views to see what is counted where. The error is triggered by the unified Microsoft storage quota, not just the 1 TB OneDrive or 100 GB mailbox numbers shown in isolation.
2. Free up Microsoft cloud storage Even with a Microsoft 365 Family subscription, if the unified storage quota is exceeded, email stops working. To get back under quota:
   • Delete or move large files from OneDrive (especially large media or backup folders).
   • Use the “view the largest files on your OneDrive” tool to quickly find and remove big items.
   • Reduce content in other services that count toward storage, such as Loop workspaces and Designer projects, by deleting unneeded pages, versions, or designs.
3. Or buy additional storage (if needed)
   • If already on Microsoft 365 Personal or Family and storage is still over the limit, additional file storage can be added on top of the 1 TB included with the subscription.
4. Wait for the change to propagate
   • After freeing space or purchasing more storage, allow some time for the storage status to update across services. Once the account is back under the unified quota, sending and receiving email will resume. Any emails sent while over quota are returned to the sender and must be resent.

If the OneDrive client on the PC still shows an incorrect full status after cleanup, unlinking OneDrive from the computer, deleting a local OneDrive file copy, and then relinking can force a resync and correct the reported usage, as seen in a similar case.

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References:

• Storage limits in Outlook.com
• Microsoft storage FAQs
• Microsoft storage quotas
• My email message doesn't send
• storage exceeded in outlook after purchasing MS 365 subscription - Microsoft Q&A