smtp bounce code
550 5.1.2Domain not found
what to do
Suppress the address
The domain itself does not accept mail. Every address at it is undeliverable, not just this one.
What the server is telling you
There is no MX record and no usable A record fallback for the domain. Often a typo in the domain, an expired registration, or a domain that was never configured for email.
Next steps
- →Suppress every address at that domain, not just this one.
- →Check the spelling of the domain first — this is what a typosquat miss looks like.
Commonly returned by: Everything
Find these before you send, not after
Paste a list and see which addresses sit on domains that accept no mail, which are one character from a real inbox, and which are on catch-all domains where nothing can tell you anything. Free, no signup, nothing stored.
Check a list →