Some sequencers and deliverability checkers will flag PTR or reverse DNS (rDNS) as "failing" or "missing" for the servers your mailboxes send from. If you've seen this warning, you don't need to take any action — it does not mean your setup is broken, and it does not hurt your inbox placement.
Why this happens
Our sending infrastructure is purpose-built for cold email at scale. To protect the health of your domains, the sending IP addresses rotate over time rather than staying fixed. Because a checker tool inspects a single IP at a single moment, it may not find a matching reverse DNS record and will report a "fail." That's a limitation of how these tools test — not a problem with your mailboxes.
What actually matters for deliverability
SPF, DKIM, and DMARC — these authentication records are what inbox providers check, and we manage them for your Maildoso domains automatically.
Sending reputation and engagement — consistent warmup and sensible daily volume matter far more than a static reverse DNS entry.
For modern cold email, a fixed PTR/rDNS record is not required for inbox placement.
What you should do
You can safely ignore a standalone PTR/rDNS warning from a third-party checker.
Keep your warmup running and your sending volumes reasonable.
Make sure your authentication (SPF, DKIM, DMARC) is passing — for Maildoso-managed domains it already is.
If you're seeing an actual deliverability problem — messages landing in spam, unexpected bounces, or a drop in replies — contact us and we'll review your specific case rather than relying on a single automated check.