4.x.x transient failure
SMTP Error Code 422: Meaning, Causes and How to Fix It
SMTP 422 is a temporary (transient) failure.
The recipient's mailbox is over its size limit and cannot take more mail right now. It is a temporary state, so delivery can resume once the recipient frees up space.
- Class
- 4xx transient
- Bounce type
- Soft bounce
- Highest severity
- Varies
- Responses on record
- 1
BarracudaSMTP 422 responses from spam filters
How spam-filtering gateways phrase a 422 rejection.
Barracuda1 response
SMTP 422 questions
›Is SMTP 422 a hard bounce or a soft bounce?
It is a transient failure, so a soft bounce. The sending server queues the message and retries it automatically for a while (often 24 to 72 hours) before it gives up.
›What causes an SMTP 422 error?
The recipient's mailbox is over its size limit and cannot take more mail right now. It is a temporary state, so delivery can resume once the recipient frees up space. The exact reason varies by receiver, which is why this page lists the specific 422 responses recorded for Barracuda.
›How do I fix an SMTP 422 bounce?
Read the enhanced status code and the message text, not just the number. Wording that names the recipient (user unknown, mailbox unavailable) means correct or remove the address. Wording that names authentication or reputation (SPF, DKIM, DMARC, blocklist) means fix that on the sending side, or clear the listing. Every response on this page has its own guidance.