# 553 5.1.2: we weren't able to find the recipient domain

URL: https://iblockspam.com/smtp-errors/553-5-1-2
Last updated: 2026-11-03

Code: 553 5.1.2 (permanent failure, the message bounced)
Provider: Gmail / Google Workspace

The part of the recipient address after the @ isn't a domain that can receive mail, usually because of a typo, extra punctuation or a domain that has expired.

What the bounce says:

```
553 5.1.2 We weren't able to find the recipient domain. Please check for any spelling errors and make sure you didn't enter any spaces, periods, or other punctuation after the recipient's email address.
```
Gmail's text for 553 5.1.2, as listed in Google's SMTP errors reference.

RFC 3463 defines X.1.2 as "Bad destination system address": the destination system in the address doesn't exist or can't accept mail, which for internet mail means the part to the right of the @ is invalid for mail. RFC 3463 says the code is only useful for permanent failures. RFC 5321 defines 553 as "Requested action not taken: mailbox name not allowed".

Gmail's text spells out the usual causes: a spelling error in the domain, or spaces, periods or other punctuation typed after the address. Google's bounce help gives examples such as john.doe@gmal.con and an address with dots at the end. A domain that has expired, or that never published mail records, fails the same way.

Fix the address and send again. If the domain looks right, look it up: a quick MX lookup shows whether it publishes mail servers. If the domain exists but has no MX record and no address record, or publishes a null MX, it doesn't accept mail, and you need another way to reach the person.

## Common causes

- A typo in the domain, such as gmal.com, outlok.com or a wrong ending like .con.
- Spaces, periods or other punctuation after the address, often from copy and paste.
- The recipient's domain has expired or was never set up for email.
- An old address saved in contacts or auto-complete for a company that changed domains.

## How to fix it (sender)

- Check the address character by character, especially the domain and its ending.
- Delete the saved contact or auto-complete entry and type the address again.
- Run an MX lookup on the domain to see whether it accepts mail.
- If the domain no longer exists, ask the person for a current address another way.

## How to fix it (recipient or admin)

- If people report this error for your real domain, check that the domain hasn't expired and that its MX records are published.

**Q: What's the difference between 553 5.1.2 and 550 5.1.1?**
550 5.1.1 means the domain is fine but the mailbox doesn't exist. 553 5.1.2 means the domain itself, the part after the @, can't be found or can't receive mail.

**Q: The domain is spelled right. Why does Gmail still say it can't find it?**
The domain may have expired, or it may not publish mail records. Run an MX lookup: if it shows no mail servers or a null MX, the domain doesn't accept mail and only its owner can fix that.

Sources:
- Gmail SMTP errors and codes (Google Workspace Admin Help): https://knowledge.workspace.google.com/admin/support/troubleshooting/gmail-smtp-errors-and-codes
- RFC 3463: Enhanced Mail System Status Codes: https://www.rfc-editor.org/rfc/rfc3463
- Fix bounced or rejected emails (Gmail Help): https://support.google.com/mail/answer/6596

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