554: reverse DNS does not meet GMX requirements
GMX refused the connection because the reverse DNS (PTR) record of your IP looks generic or dynamic. GMX expects a fixed IP with its own mail host name.
- GMX, WEB.DE
- Provider
- Permanent (5xx)
- Class
- Sources checked
- Author
At a glance
- Code
- 554
- Provider
- GMX, WEB.DE and mail.com
- Temporary or permanent
- PermanentRefused for good: the message comes back to the sender, and resending it gets the same answer.
- Who has to act
- The sender. The fix is on the sending side: your domain, your server or your list.
- What the server says
554 Bad DNS PTR resource record
What it means
GMX checks the PTR record of every connecting IP. Case r0601 means the record exists but does not meet the GMX requirements: typically it is the default name a hosting or access provider gives every address, built from the IP itself, such as 123-123-123-123-static.provider.tld. GMX reads names like that as a sign of a dynamic address or an unmanaged server and refuses the connection with 554. The fix is to send from a permanently assigned IP whose PTR record carries a fully qualified name of your own, in the format GMX recommends, mail.yourdomain.tld.
Common causes
- The PTR record is the provider default, built from the IP address.
- The IP is dynamically assigned, for example a home or office connection.
- The server's PTR name was never changed after the machine was set up.
How to fix it
- 01Send from a static IP address assigned to your mail server.
- 02Ask the owner of the IP range (your host or ISP) to set the PTR record to a name in your own domain, such as mail.yourdomain.tld.
- 03Make sure that name resolves back to the same IP, as GMX also checks forward-confirmed reverse DNS.
- 04If you cannot change the PTR record, send through a relay that has proper reverse DNS.
Sources
What this page rests on, checked on 20 Oct 2026. The explanation is ours; the reply text is the server's.
- GMX Postmaster case r0601: 554 Bad DNS PTR resource recordpostmaster.gmx.net
Related codes
- 554No reverse DNS for your IP.GMX refused the connection because the IP address of your mail server has no PTR record, so it is not tied to any domain name in DNS.
- 554Forward-confirmed reverse DNS failed.GMX refused the connection because the name in your IP address PTR record does not resolve back to that same IP, so the FCrDNS check failed.
- 554Reverse DNS does not meet IONOS policy.IONOS refused your mail because the PTR record of your IP does not meet its policy, typically a generic or dynamic-looking provider name.
- 554Transaction failed.The server permanently refused the transaction, often after receiving the message data or straight away when the connection opened.
554 at other providers
- 554Permanent rejection (554).Yahoo or AOL rejected the message for good with a 554. Yahoo uses this code for several problems, from failed authentication to unacceptable content, so the wording of the reply tells you which.
- 554Failed authentication.Yahoo or AOL refused the message because it failed the checks that confirm the sending domain, such as DKIM against the domain's policy. Yahoo lists this among its permanent 553 and 554 errors.
- 554Recipient does not exist.The Yahoo or AOL account you wrote to does not exist. The failure is permanent: check the address with the recipient, and remove it from any list.
- 554No reverse DNS (PTR) record.Xfinity refused the connection because your sending IP has no PTR record. Every server sending to Xfinity needs valid reverse DNS, so the owner of the IP must add one.
- 554No reverse DNS for your IP.IONOS refused your mail because the IP address of your mail server has no domain name assigned to it in DNS (no PTR record).
Further reading
All 57 GMX, WEB.DE codesEvery code in the wikiPaste your own bounce