Permanent failure — do not retry
SMTP 552
exceeded storage allocation
SMTP 552 means the server aborted the action because of a storage limit. RFC 5321 defines it as "requested mail action aborted: exceeded storage allocation". In practice it means either the recipient's mailbox is full (552 5.2.2) or your message is larger than the server accepts (552 5.3.4).
How it appears
552 Requested mail action aborted: exceeded storage allocation
552 5.2.2 Mailbox full
552 5.3.4 Message size exceeds fixed limit
What causes it
- The recipient's mailbox is over quota.
- The message, including attachments, is bigger than the receiving server's size limit.
- The message has more recipients than the server allows in one transaction.
How to fix it
In order — try the first one first.
- Check the enhanced code. 5.2.2 is a full mailbox, 5.3.4 is a message that is too big.
- For size, send a link to the file instead of attaching it. Encoded attachments grow by about a third in transit.
- For a full mailbox, try again later. If it stays full for weeks, remove the address.
Common questions
- What does SMTP 552 mean?
- SMTP 552 means the server aborted the action because of a storage limit. RFC 5321 defines it as "requested mail action aborted: exceeded storage allocation". In practice it means either the recipient's mailbox is full (552 5.2.2) or your message is larger than the server accepts (552 5.3.4).
- Should I retry a 552 error?
- No. 552 is a permanent failure, so the message will never be delivered no matter how many times you try. Remove the address — repeated sends to permanent failures are one of the main signals mailbox providers use to throttle a sender.
- How do I fix SMTP 552?
- Check the enhanced code. 5.2.2 is a full mailbox, 5.3.4 is a message that is too big.
Specific 552 replies
Last reviewed 2026-09-11