5.2.2: mailbox 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.
- Standard
- Provider
- Permanent (5xx)
- Class
- Sources checked
- Author
At a glance
- Code
- 5.2.2
- Provider
- Standard SMTP codes
- Temporary or permanent
- PermanentRefused for good: the message comes back to the sender, and resending it gets the same answer.
- Who has to act
- Either side, depending on the cause. Start with the checks below that are yours.
- What the server says
5.2.2 Mailbox full
What it means
X.2.2 reports that the recipient is over quota. RFC 3463 notes that the recipient can free space by deleting mail and calls it a persistent temporary failure, which is why servers send it in both classes. 4.2.2 means the sending server keeps the message and retries; if space is freed in time, the message arrives. 5.2.2 means the receiving server decided to return it now, often with reply code 552. One full-mailbox bounce is no reason to drop a contact, but an address that stays full send after send usually belongs to an abandoned account.
Common causes
- The owner has used up their storage quota and has not deleted anything.
- An abandoned account that keeps receiving mail nobody reads.
- Large attachments that fill a small quota quickly.
How to fix it
- 01Send again later, or let the retries run if the code was 4.2.2.
- 02Tell the recipient by another channel that their mailbox is full.
- 03If the address stays full across many sends, treat it as inactive and stop mailing it.
- 04Recipient admins: raise the quota or archive old mail.
Sources
What this page rests on, checked on 20 Oct 2026. The explanation is ours; the reply text is the server's.
Related codes
- 552Storage allocation exceeded.The receiving server aborted the message because it exceeded a storage limit, usually a full mailbox or a message larger than allowed.
- 452Insufficient system storage.The receiving server is short of storage or has hit a limit, such as the number of recipients in one message, and asks the sender to try again later.
- 4.3.1Receiving system out of storage.The receiving mail server has run out of storage space, so it cannot accept messages for now; the sending server keeps the message and retries later.
- 5.2.3Message too large for this mailbox.The message is bigger than the size limit set for this particular mailbox, which an administrator set lower than the system-wide limit.
5.2.2 at other providers
- 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.
- 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.
- 554 5.2.2Mail-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.
Further reading
All 105 standard codesEvery code in the wikiPaste your own bounce