Reverse DNS and sending mail from your VPS

Reverse DNS works the other way round: it links your IP address back to a name. Receiving mail servers check this. You also see that name in logs and with some services.

Setting up reverse DNS

You set the reverse DNS in the VPS screen, on the ISO and rDNS tab, under Reverse DNS. Choose a name that really points to your VPS, for example web1.example.com, or mail.example.com if your server sends mail.

Your domain's DNS is at WebOké: choose the Domain, enter the subdomain under Name (for example mail) and click Set up DNS and rDNS. The A and AAAA records are then created for you, and the reverse DNS follows within a few minutes, for both IPv4 and IPv6.

Your domain is somewhere else: first create an A record pointing to your IPv4 address and an AAAA record pointing to your IPv6 address yourself. Then enter the full name under Reverse DNS and click Request. If the name doesn't point to your VPS yet, you'll get a message and nothing happens.

Check it:

dig +short -x 203.0.113.10
web1.example.com.
dig +short -x 2001:db8::10
web1.example.com.

More background: Reverse DNS (PTR): from number back to name.

Sending mail from your VPS

Outgoing traffic to port 25 (mail between mail servers) is blocked on your VPS by default. This way a hacked VPS can't send spam that would get our IP addresses onto blacklists.

For most uses you don't need port 25. Let your website, WordPress, n8n or Uptime Kuma send mail through a mailbox, logging in on port 587 (STARTTLS) or 465 (SSL/TLS). You can use an email address from your hosting package or mail package at WebOké. These ports are open. The details: All settings at a glance: servers, ports and security.

Do you really want to run your own mail server? Then you need:

• proper reverse DNS, matching the name your mail server announces itself with;
• an SPF record with your VPS's IP addresses, DKIM signing and a DMARC record (see DNS helpers: MX, SPF, DMARC, CAA and SRV);
• port 25 open. Request this by submitting a ticket (see Submitting a ticket).

More on this: Sending mail from your VPS and setting up reverse DNS.

Please note: Running your own mail server is a lot of work: spam filters, blacklists, updates and monitoring. For ordinary mail, a mail package is almost always the better choice.