Mail Server Hostname & Reverse DNS (PTR) Setup
Configure a mail hostname and reverse DNS (PTR) for your server IP.
Correct forward and reverse DNS is an important mail-server setup step. Some receiving systems may reject or filter messages when the sending IP has missing or inconsistent reverse DNS. It does not guarantee inbox placement.
Forward Resolution: mail.yourdomain.com ──────(DNS A Record)──────► 198.51.100.1
Reverse Resolution: 198.51.100.1 ──────(rDNS / PTR)────────► mail.yourdomain.com1. Configure DNS: Host 'A' Records
Add the A records pointing your mail server, web dashboard, and docs platform to your VPS public IPv4:
| Type | Name / Host | IPv4 Address | Proxy Status | Purpose |
|---|---|---|---|---|
A | mail | <YOUR_VPS_IP> | DNS Only / Unproxied | Mail server hostname and forward lookup |
A | emitmail | <YOUR_VPS_IP> | DNS Only or Proxied | EmitMail Web Dashboard & REST API (https://emitmail...) |
A | emitdocs | <YOUR_VPS_IP> | DNS Only or Proxied | EmitDocs Documentation Platform (https://emitdocs...) |
DNS Only for Mail Server Hostname
If using Cloudflare or a CDN proxy service, do NOT enable the proxy (e.g. Cloudflare Orange Cloud) for mail.yourdomain.com. Proxies only handle HTTP/HTTPS web traffic (ports 80/443) and will drop raw SMTP Port 25 connections. Keep mail DNS Only / Grey Cloud. emitmail and emitdocs can safely be proxied or unproxied.
2. VPS Provider Networking Panel: Reverse DNS (PTR)
Log in to your hosting provider's management console (DigitalOcean, Hetzner, Vultr, Linode, AWS) and locate the Networking / IPv4 tab:
Find your primary public IPv4 address.
Click Edit PTR / Reverse DNS.
Set the PTR value to your exact mail server hostname:
mail.yourdomain.com3. Verifying FCrDNS Verification
From your local machine or VPS terminal, run dig:
# 1. Test Forward A Resolution
dig +short A mail.yourdomain.com
# Output should return: <YOUR_VPS_IP>
# 2. Test Reverse PTR Resolution
dig +short -x <YOUR_VPS_IP>
# Output should return: mail.yourdomain.com.Confirm the A record resolves to the sending IP and the PTR record resolves to the configured mail hostname. PTR changes are managed by your IP hosting provider and may take time to propagate. This configuration is one part of mail authentication and does not guarantee delivery.