Phase 7: Configure reverse DNS

Normal DNS maps a hostname to an IP address:

mail.example.com → 203.0.113.10

Reverse DNS maps the IP address back to a hostname:

203.0.113.10 → mail.example.com

Configure this in the VPS provider’s control panel.

Edit the PTR record for the VPS IPv4:

203.0.113.10

Set it to:

mail.example.com

Changing the PTR does not modify:

• A records

• CNAME records

• Dokploy domains

• Other subdomains

• Traefik routes

• Containers

Verify:

dig +short A mail.example.com
dig +short -x 203.0.113.10

Expected:

203.0.113.10
mail.example.com.

Do not publish an AAAA record until IPv6 mail delivery is deliberately configured.