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Microsoft (Outlook.com and Microsoft 365) · permanent error

554 5.2.2: mail-enabled public folder is full

Delivery to a mail-enabled public folder failed because the folder, the organization default, or its public folder mailbox reached its quota.

Microsoft
Provider
Permanent (5xx)
Class
Sources checked
By , email deliverability consultant
Author

At a glance

Code
554 5.2.2
Temporary or permanent
PermanentRefused for good: the message comes back to the sender, and resending it gets the same answer.
Who has to act
The recipient's side. Their mail admin has to change something; you can tell them.
What the server says
554 5.2.2 mailbox full; STOREDRV.Deliver.Exception:QuotaExceededException.MapiExceptionQuotaExceeded

What it means

Microsoft documents this 554 5.2.2 report for mail sent to a mail-enabled public folder in Exchange Online. One of three quotas has been reached: the post quota set on that folder, the organization's default public folder post quota, or the quota of the public folder mailbox that holds the folder's content. The sender sees the usual mailbox full message, but the fix is entirely on the recipient side, where an admin raises the right quota or lets the content split into a new public folder mailbox.

Common causes

  • The folder's own ProhibitPostQuota has been reached.
  • The organization's DefaultPublicFolderProhibitPostQuota has been reached.
  • The content public folder mailbox has hit its quota and auto-split has not created a new one.

How to fix it

  1. 01Tell the recipient organization's admin; senders cannot fix it.
  2. 02Admins: compare the folder's TotalItemSize (Get-PublicFolderStatistics) with its ProhibitPostQuota and raise the folder quota if needed.
  3. 03If the organization default is the limit, raise DefaultPublicFolderProhibitPostQuota with Set-OrganizationConfig, avoiding very large per-folder values that hinder auto-split.
  4. 04If the content mailbox is full and auto-split has not created a new one, open a request with Microsoft Support.

Sources

What this page rests on, checked on 20 Oct 2026. The explanation is ours; the reply text is the server's.

  1. 5.2.2Submission quota exceeded.The sender went over the Exchange Online recipient or message rate limit, so Microsoft 365 refused to accept more mail from the account.MicrosoftPermanent
  2. 5.2.2Mailbox full.The recipient's mailbox has reached its storage quota, so the server will not take more mail until the owner deletes messages or gets more space.StandardPermanent

5.2.2 at other providers

  1. 552 5.2.2Mailbox full and inactive.The recipient's Google account is out of storage and no longer in use, so Gmail rejected your message permanently.GmailPermanent

All 111 Microsoft codesEvery code in the wikiPaste your own bounce

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