Ensure your sending IP has a valid PTR record pointing back to your domain — a basic legitimacy check used by every major receiver.
⚡ Monitored by EmailExacto IntelligenceReverse DNS (rDNS) maps an IP address back to a hostname using PTR records stored in in-addr.arpa zones. PTR records are set by the IP address owner — typically your hosting provider — at their request. For email senders, a valid PTR record is a basic legitimacy signal that receiving mail servers check as one of their first filters. Both Google and Microsoft require it as a hard prerequisite.
A PTR lookup reverses the IP octets and queries the in-addr.arpa zone:
Many receivers also perform forward-confirmed rDNS (FCrDNS): they resolve the PTR hostname back to an IP and verify it matches the original IP. A PTR and forward A record that match passes FCrDNS. Contact your hosting provider to set PTR records — they control the reverse zone for your IP allocation.
Many mail servers — particularly in enterprise sectors — reject email from IPs without valid PTR records. Microsoft Outlook/Hotmail enforces this strictly. Spamhaus PBL lists IP ranges without PTR records as "policy" listings. Even when not causing rejection, a missing PTR increases spam scores across most filtering systems.
EmailExacto's sending infrastructure has a valid PTR record and passes FCrDNS checks. The platform monitors MX host IPs as part of daily blacklist and DNS checks.
✓Set a PTR record for every IP you use to send email — contact your hosting provider.
✓Ensure your PTR hostname has a forward A record pointing back to the same IP.
✓Use a hostname that includes your sending domain — generic values like server1.provider.com look less legitimate.
✓Verify your PTR record after setting it — propagation can take up to 24 hours.
✓Check if your IP is on Spamhaus PBL — a listing often indicates a missing or generic PTR.
✓If using a shared ESP IP, verify the ESP has configured PTR correctly.
Expert-written training delivered to your inbox every Tuesday. No spam. Unsubscribe anytime.
Join thousands of senders building better email habits.