Outlook limit

Question

I don't have access to my 1TB Outlook storage. I think it may be due to confusion of two email addresses.

Answer 1

Do you have a Microsoft 365 personal or family subscription? If so, the 1TB is for your OneDrive storage, and when it comes to your mailbox storage, it upgrades it to 100GB, not 1TB.

So, if you shouldn't be seeing 1TB, but 100GB.

Tell me if you are seeing 100GB, if not, was the subscription purchased very recently, such as within the last 48 hours?

What do you mean by two email addresses? If you tell me more about that, I can determine if that is the issue.

Answer 2

Outlook.com email storage and Microsoft cloud storage are separate and both can affect access.

Key points from the storage model:

1. Outlook.com mailbox storage
   • Free Outlook.com accounts get 15 GB of email storage.
   • Microsoft 365 subscribers get a 100 GB mailbox per person for Outlook.com.
   • If the email storage quota is exceeded, sending and receiving email in Outlook.com is blocked and senders get a “mailbox full”/quota error until usage is reduced.
2. Microsoft cloud (OneDrive/Unified) storage
   • Free Microsoft accounts get 5 GB of cloud storage shared across OneDrive files, Outlook.com attachments, and Microsoft 365 apps.
   • A Microsoft 365 subscription increases OneDrive/cloud storage (for example, plans that include 1 TB), but the mailbox limit is still 100 GB.
   • If Microsoft unified storage is exceeded, the following happens even if the mailbox itself is not full:
     • Cannot upload, edit, or sync new files to OneDrive; existing files become read‑only.
     • Cannot send or receive email in Outlook.com.
     • Cannot send or receive Microsoft Teams messages with attachments.
     • After 6 months over quota, OneDrive and its files may be deleted.
3. Impact of multiple email addresses
   • Storage is tied to the Microsoft account, not just to a single email alias.
   • It is possible to receive “storage limit exceeded” notices on one email address while checking storage usage under a different sign‑in, if there are two different Microsoft accounts involved.
   • In similar cases, users have discovered that an older Microsoft/OneDrive profile (using a different email address) was actually over the 5 GB limit, even though the newer account showed plenty of space. Cleaning or emptying storage on the correct/older account stopped the warning emails.
4. How to restore access when storage is blocking Outlook
   • If the problem is unified/cloud storage over 5 GB:
     • Either free up space (delete or move files/attachments, then empty recycle bin in OneDrive) using the Microsoft account that is actually over quota, or
     • Purchase a Microsoft 365 subscription or additional storage for that same account to raise the storage quota.
   • If the problem is email storage:
     • Use Outlook.com Settings → Storage to see folder usage and permanently delete items (including older than 3, 6, or 12 months) until usage is below the mailbox limit.
   • After freeing space or upgrading, it can take some time for the change to propagate before Outlook sending/receiving is fully restored.
5. When 1 TB is available but Outlook still shows blocked
   • If a Microsoft 365 subscription with 1 TB OneDrive is active but Outlook still reports storage issues, typical causes in similar cases have been:
     • The device or app is still linked to an older OneDrive/Microsoft account that is over the 5 GB free limit.
     • The OneDrive client needed to be unlinked from the PC, a problematic file removed, and then OneDrive relinked so that storage status refreshed correctly.
   • Once the correct account is linked and storage is under quota, Outlook email access resumes.

To regain access to the full Outlook/OneDrive storage, ensure that:

• Sign‑in is with the Microsoft account that actually owns the Microsoft 365 subscription and 1 TB storage.
• Any older or secondary Microsoft accounts that are over the 5 GB free limit are either cleaned up or upgraded, especially if they are still connected on a device.

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References:

• Storage limits in Outlook.com
• Mailbox storage limits in Outlook
• Microsoft storage limit exceeded - Microsoft Q&A
• my outlook email is not delivered - Microsoft Q&A
• storage exceeded in outlook after purchasing MS 365 subscription - Microsoft Q&A
• How to Fix outlook - Microsoft Q&A
• Storage showing full - Microsoft Q&A