mailbox_full
The mailbox is over its storage quota
The server accepted the address but answered that the mailbox cannot take more mail right now. The account is real and may be read again once space is cleared.
- appears in
- reason, smtp_reason
- verdict
- risky
- risk weight
- +20
- credits
- 1 credit, like every deliverable or risky answer. Repeats of the same address are free for 7 days.
What it means
The handshake reached the recipient check and the server replied with a "mailbox full" class response (a 452 or 552). The mailbox exists, it just has no room, which is why the verdict is risky rather than undeliverable.
As a reason it sets the verdict. As an smtp_reason it explains a probe result on a lookup that another signal may already have settled; the same value appears in both fields for the same address.
What to do
Keep the address but hold the send and retry in a few days. For transactional mail that matters, use another channel meanwhile.
Example response
{
"email": "[email protected]",
"deliverable": "risky",
"reason": "mailbox_full",
"smtp_reason": "mailbox_full",
"mailbox_exists": true
}Abbreviated: a real answer carries all 27 fields, listed in the verify-email reference.
Related
- likely_typo · the domain is a known misspelling of a real mail provider
- disposable · the domain belongs to a disposable, temporary email provider
- implicit_mx · the domain has no MX record and relies on the address-record fallback
- role · a shared role inbox such as info@ or support@ rather than a person
- catch_all · the server accepts every address at the domain, so the mailbox cannot be confirmed
- All verdict reasons
- Verdicts and the risk score
- API reference
markdown version: /docs/reasons/mailbox_full.md