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Reverse DNS (rDNS) helps receiving servers verify that your sending IP matches your domain name. Forward-confirmed rDNS reduces the chance that your mail is rejected or filtered as suspicious.

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What is PTR/rDNS

A PTR record maps an IP address back to a hostname. It is the reverse of a regular DNS A record, which maps a hostname to an IP. Receiving mail servers often check that the IP sending them mail has a valid PTR record, and that the hostname it resolves to points back to the same IP (forward-confirmed rDNS).

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Why receivers check rDNS

Mailbox providers and spam filters use rDNS as a basic trust signal:
  • IPs without PTR records may be treated as less reputable.
  • Mismatched forward and reverse DNS looks like spoofing or misconfiguration.
  • Some receivers reject mail outright from IPs that fail this check.

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Who sets the PTR record

The owner of the IP address controls PTR records. Because mySMTP owns the IP addresses allocated to your account, mySMTP sets and manages PTR records for all dedicated IPs. You cannot add a PTR record at your own DNS provider. If you need a custom PTR name for your dedicated IP (for example, to match your sending domain), contact support@mysmtp.com with your request.
Shared IP plans are only available to customers in Denmark. PTR for shared IPs is managed by mySMTP and cannot be customized.

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How to check your current PTR

You can verify the current PTR record for your IP using any of these methods.
Run this command, replacing YOUR_IP with your sending IP:
Example output:
Always use the hostname from your setup email. relayxx.mysmtp.com is an example. Shared IP (DK only) customers use mail.mysmtp.com.

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Shared IP (DK only) behavior

On shared IP plans, the PTR record is set by mySMTP to a shared hostname. Individual customers cannot request custom PTR names on shared IPs. If you require a custom PTR, consider upgrading to a dedicated IP plan.