# SMTP 552: requested mail action aborted, exceeded storage allocation URL: https://iblockspam.com/smtp-errors/552 Last updated: 2026-10-09 Code: 552 (permanent failure, the message bounced) Provider: Standard (RFC) A storage or size limit stopped the message: the recipient's mailbox is full, or the message is larger than the receiver accepts. What the bounce says: ``` 552 5.3.4 Your message exceeded Google's message size limits. ``` Start of Gmail's text for an oversized message, as listed in Google's SMTP errors reference. RFC 5321 defines 552 as "Requested mail action aborted: exceeded storage allocation". It is a permanent reply, but the enhanced code tells you which limit you hit. - **5.2.2 Mailbox full.** The recipient is over their quota. RFC 3463 says this code should be used as a persistent transient failure, because the recipient can delete messages to make room. - **5.2.3 Message length exceeds administrative limit.** A per-mailbox size limit lower than the server's general limit. - **5.3.4 Message too big for system.** The message is larger than the server's per-message limit. Gmail returns 552 5.3.4 for messages, attachments or headers over its limits. One historical quirk: RFC 821 used 552 for "too many recipients". RFC 5321 corrects this to 452 and asks clients to treat a 552 for too many recipients as temporary. And RFC 5321's size-limit section gives "552 Too much mail data." as an example reply for a message that is too large. ## Common causes - The recipient's mailbox is full. - The message, with attachments, is larger than the receiver accepts. - Headers are larger than the receiver accepts. - An older server reporting too many recipients with 552. ## How to fix it (sender) - For a size error, send large files as a download link instead of an attachment. - Remember that attachments grow by about a third when encoded for email. - For a full mailbox, contact the recipient another way and resend once they have cleared space. ## How to fix it (recipient or admin) - Delete or archive old mail, or ask your admin for a larger quota. - If partners need to send large files, agree on a file-sharing method. **Q: How do I know if 552 means mailbox full or message too big?** Read the enhanced code. 5.2.2 means the recipient's mailbox is full; 5.3.4 means your message is larger than the receiving system allows; 5.2.3 means a per-mailbox size limit. **Q: Why does my 20 MB attachment fail when the limit is 25 MB?** Email usually encodes attachments with Base64 (RFC 2045), which turns every 3 bytes into 4 characters, so files grow by about a third. A file close to the limit can end up over it once encoded. Sources: - RFC 5321: Simple Mail Transfer Protocol (reply codes, section 4.2): https://www.rfc-editor.org/rfc/rfc5321#section-4.2 - RFC 3463: Enhanced Mail System Status Codes: https://www.rfc-editor.org/rfc/rfc3463 - Gmail SMTP errors and codes (Google Workspace Admin Help): https://knowledge.workspace.google.com/admin/support/troubleshooting/gmail-smtp-errors-and-codes - RFC 2045: MIME part one, section 6.8 (Base64 encoding): https://www.rfc-editor.org/rfc/rfc2045#section-6.8 --- Source: iBlockSpam, https://iblockspam.com/smtp-errors/552 (this is a Markdown copy; the HTML page is canonical). Quote with attribution and a link. Site index for AI assistants: https://iblockspam.com/llms.txt