550 5.4.4: Unable to route: no working mail server
The sending server couldn't find anywhere to deliver the message for that domain.
Hard bounce The address is bad. Don't keep sending to it.
What the bounce message looks like
The wording changes from one provider to another. These are typical examples:
550 5.4.4 Unable to route: no mail hosts for domain550 5.4.4 SMTPSEND.DNS.NonExistentDomain; nonexistent domainCommon causes
- A domain typo
- An expired domain
- Broken or missing MX records
How to fix it if you sent the email
- Check the domain spelling.
- Look up the domain's MX records with the DNS checker.
If you manage the receiving or sending mail system
- Fix the domain's MX records so they point to a working mail server.
Free tool: paste the full bounce into the bounce message decoder to get a plain-English reading of every code in it.
Questions people ask
- What does 550 5.4.4 mean?
- The sending server couldn't find anywhere to deliver the message for that domain.
- Is 550 5.4.4 a hard or soft bounce?
- Hard bounce. The address is bad. Don't keep sending to it.
- Should I remove the address after a 5.4.4 bounce?
- Yes. Remove it from your list, or confirm a new address with the person first.