DIAGNOSTIC PLAYBOOK
A receiver rejects your sending IP's reverse DNS
Some receivers require consistent reverse DNS for sending infrastructure. PTR data is normally controlled by the IP operator, so changing the From domain's TXT records may not address the rejection.
HealthCheck Email editorial team · · Examples are illustrative
How to investigate
- Capture the source IP and receiver's exact reverse-DNS diagnostic.
- Check its PTR answer and whether the returned hostname resolves as expected.
- Ask the IP or mail-service operator to correct the supported reverse and forward DNS configuration.
What this looks like
ILLUSTRATIVE EXAMPLE
A new dedicated sending IP has no PTR record even though SPF and DKIM pass. The receiving provider rejects it for the infrastructure issue.
A mistake to avoid
For shared email services, do not create an arbitrary PTR-like TXT record in your domain. The address operator controls reverse DNS.
Keep the result in context
A successful handoff, a delivered event and an inbox placement are different observations. Record the receiving provider, send time, SMTP response and affected stream before comparing results. DNS fixes address authentication or routing; they cannot establish consent or guarantee placement.
Take the next step
Use the related check to gather evidence, then compare it with the affected message or service. Keep the result and time with your notes so a later change can be distinguished from the original problem.
Sources and further reading
The protocol references below explain the underlying behavior. Your sending or DNS provider supplies the account-specific settings for its service.