554 5.2.2: Microsoft 365 mailbox full or quota hit
554 5.2.2Mailbox full or submission quota exceededPermanent: retrying will not helpFrom Microsoft 365 and Outlook.com
554 5.2.2 mailbox full; STOREDRV.Deliver.Exception:QuotaExceededException.MapiExceptionShutoffQuotaExceeded
What it means
RFC 3463 defines X.2.2 as mailbox full. In Exchange Online you see it in two situations. The common one is the recipient’s mailbox reaching its prohibit receive quota: the store driver (STOREDRV) tries to write the message and the mailbox refuses it, which produces the QuotaExceededException text above.
The second is a submission quota on the sending side: your own mailbox exceeded a message rate or recipient rate limit, and Exchange returns 5.2.2 to you with wording about a submission quota. Read the text after the code to know which side is full.
Exchange Online returns this as a permanent failure. The message will not be retried, even though the condition is often fixed within minutes once someone clears space.
Likely causes
- The recipient mailbox reached its storage limit, often because of large attachments or a full Recoverable Items folder.
- A shared mailbox without a license grew past its 50 GB cap.
- Litigation hold or retention kept deleted items, so the user emptied Deleted Items but the quota stayed full.
- On the sending side, a script or app submitted too many messages per minute from one mailbox.
How to fix it
- Sender: tell the recipient through another channel that their mailbox is full, then resend after they confirm.
- Recipient: delete large items, empty Deleted Items, and archive old mail to an online archive.
- Recipient admin: check mailbox statistics, including Recoverable Items, and enable auto expanding archiving or assign a larger license if needed.
- If the text mentions a submission quota, slow down the sending application or spread the load across several mailboxes.
Checks that apply
- MX Lookup Confirms the recipient domain really is hosted on Microsoft 365, so the STOREDRV text applies and you know which admin to contact.
- MailFlow Monitor After space is freed, a test message confirms delivery works again without bouncing a real one.
FAQ
- Will Exchange Online retry when the mailbox has space again?
- No. The 5.2.2 is final for that message, so it must be sent again.
- The user deleted mail but still bounces. Why?
- Deleted items move to Recoverable Items, which still counts toward quota when a hold is in place. An admin has to check that folder.