Skip to content

Own mail server, mail lands in spam, likely missing or wrong PTR

A PTR record (reverse DNS) maps an IP back to a hostname. Many mail receivers (Gmail, Outlook) reject or downgrade mail from IPs without a matching PTR. You do not set the PTR in your own zone, but at the party that owns the IP block (your hosting or ISP).

Try this first

  1. 1Check the current PTR with dig -x 1.2.3.4 or host 1.2.3.4. Empty output or a generic ISP name (e.g. cust-1-2-3-4.kpn.net) is a red flag.
  2. 2Request a PTR from hosting or ISP that exactly matches your mail server's A record, so mail.vectel.nl must resolve to 1.2.3.4 and 1.2.3.4 must resolve back to mail.vectel.nl.
  3. 3Make sure the mail server's HELO/EHLO banner uses the same hostname as the PTR, otherwise spam filters still trigger.
  4. 4Verify with mxtoolbox.com or mail-tester.com that PTR, SPF, DKIM and DMARC are all green.
  5. 5With IPv6 mail servers a PTR is required too, do not forget it, or Google rejects mail sent over AAAA.

When to bring us in

If hosting refuses to set a PTR or you are on a shared IP, switching to a sending service (Postmark, Mailgun) is usually better than continuing to fight it.

See also

None of the above fits?

Describe your situation below. We pass your input plus the steps you already saw to our AI and return tailored next-step advice. If it's too risky to DIY, we'll say so.

Who are you?

For the AI question we need your email and company, so we can follow up if the AI gets stuck, and to prevent abuse.

Limited to 2 questions per hour and 5 per day, kept lean so the AI stays useful. For more, contacting us directly works better for you and us.

Or skip the DIY entirely

Our Managed IT clients do not look these things up. One point of contact, a fixed monthly price, resolved within working hours.