Outlook storage still full after upgrade

When Outlook.com/Hotmail still shows as full after buying the 100 GB upgrade, the issue is usually that either:

• The mailbox is still over quota and needs cleanup, or
• The Microsoft cloud storage (OneDrive + email attachments) is over its quota and blocking mail, even if the email storage itself looks fine, or
• The new quota has not refreshed yet in the client.

Use these steps end to end:

1. Confirm which quota is full (email vs. cloud storage)
   • In Outlook.com, open Settings and search for Storage.
   • Check both:
     • Email storage (mailbox size) – Outlook.com gives 15 GB free; Microsoft 365 subscribers get 100 GB.
     • Microsoft storage / Unified storage (OneDrive + attachments, etc.).
   • If you see a “Microsoft Unified Storage is full” or cloud storage full message, mail will be blocked even if the mailbox itself is under 100 GB.
2. If email storage is full or near the limit
   • In Outlook.com, go to Settings > Storage.
   • Use the folder breakdown to see which folders use the most space.
   • For each large folder, use the options to permanently delete all items, or items older than 3, 6, or 12 months, to get back under quota.
   • Note: Consumer mailboxes are capped at 100 GB even with Microsoft 365. If the mailbox is at or above 100 GB, space must be freed; the limit cannot be increased further.
3. If Microsoft cloud storage / unified storage is full
   • When Microsoft storage is exceeded:
     • Outlook.com cannot send or receive email, even if email storage is not full.
     • OneDrive becomes read-only for new uploads/edits.
   • To get back under the unified storage quota:
     • If using the free plan, either buy a subscription to increase storage or delete files in OneDrive and large attachments to free space.
     • If already on Microsoft 365 Personal/Family, additional file storage can be purchased on top of the 1 TB included, or files must be deleted to get under quota.
4. Force a refresh of the new quota
   • If the subscription was purchased recently and the quota view still looks wrong:
     • Close and reopen the Outlook mobile app, then in Settings > Account > Storage, tap the subscription type (Free plan/Premium) to force a refresh.
     • On the web, sign out of Outlook.com and OneDrive, then sign back in and recheck Email storage and Microsoft storage.
   • If the account was locked for being over quota, it can take up to a couple of hours after purchasing additional storage for the new quota to show. If it still hasn’t updated after several hours, use the support contact options in Outlook.com.
5. Understand impact while over quota
   • While cloud storage is over quota:
     • Cannot send or receive email in Outlook.com.
     • Messages sent to the account are bounced and must be resent after the quota issue is fixed.
   • While email storage is over quota:
     • Cannot send or receive email until enough messages are deleted to get under the limit.

Once both the email storage and Microsoft unified storage are under their quotas and the subscription has refreshed, Outlook.com/Hotmail will resume sending and receiving mail; no additional “sync” step is required beyond the above.

References:

• Storage limits in Outlook.com
• Microsoft storage quotas
• Microsoft storage FAQs
• What is Microsoft cloud storage?
• Can't send or receive email in Outlook.com