Permanent failure (hard bounce)
Email error 550 5.1.2: Bad destination domain (domain not found)
The domain after the @ sign cannot be found or has no mail server. There is nowhere to deliver the message.
Common causes
- A typo in the domain, for example gmial.com.
- The domain expired or was never registered.
- The domain has no MX record and no usable address record.
- A temporary DNS problem on the receiving side (rare).
How to fix it
- Fix the typo if you can tell what was meant.
- Check the domain with an MX lookup.
- If the domain is really gone, remove every address on it.
- Add typo detection at sign-up to stop these entering the list.
How to prevent it
Remove the address from your list and verify the rest before the next campaign.
Clean a whole list · MX lookup · SPF, DKIM and DMARC checker
Frequently asked questions
How do I check the domain?
Use an MX lookup. No MX record usually means the domain cannot receive email.
Is it always permanent?
Almost always. Only a short DNS outage can cause a false alarm.
Other error codes
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