Sending mail from your VPS and setting up reverse DNS

Do you want to send mail from your VPS, for example with your own mail server or from a webshop? Then there are two things that matter: port 25 and reverse DNS.

Port 25 is closed by default

Outgoing traffic to port 25 (mail between mail servers) is blocked by default. This prevents a hacked VPS from sending spam and our IP addresses ending up on blacklists, which would affect all customers.

• Sending mail through an external service or your own mailbox (port 587 or 465, with login) works fine. For most websites and webshops, that's the best choice.
• Want to run your own mail server? Open a ticket. We'll check together that everything is set up correctly and then open port 25 for you.

Reverse DNS (PTR)

Reverse DNS links your IP addresses back to a name, for both IPv4 and IPv6. Receiving mail servers check this: without proper reverse DNS, your mail often ends up in spam or gets rejected. The name must also match the name your mail server uses to identify itself (the HELO name).

Examples of a good name:

• mail.yourdomain.nl if your VPS sends mail
• server.yourcompany.nl or vps1.yourdomain.nl for general use

Setting it up

Go to the ISO and rDNS tab in your VPS screen.

• Is your domain in our DNS? Choose the domain and a name (for example mail) and click Set up DNS and rDNS. We'll create the A and AAAA record, and within a few minutes the reverse DNS for IPv4 and IPv6 will be set.
• Is your domain somewhere else? First create an A record for the name pointing to your IPv4 and an AAAA record pointing to your IPv6 (both are listed in your VPS screen) with your DNS manager. Then enter the full name under Reverse DNS and click Request: the reverse DNS will then be set correctly right away.

Check the result with dig -x your-ip-address or nslookup your-ip-address, for both addresses.

Reverse DNS with a hosting package

Don't have a VPS but a hosting package? Then you don't need to set anything up. Your mail then goes through WebOké's servers, which already have a proper reverse DNS with a name of the server itself, such as server64143.webawere.nl. That's correct: recipients check whether the reverse DNS matches the server, not whether your own domain name is included. A reverse DNS with your own domain name also isn't possible with a hosting package, since the IP address is shared by multiple customers.

Don't forget SPF, DKIM, and DMARC

For proper delivery, you also need an SPF record with your VPS IPs (ip4: and ip6:), DKIM signing by your mail server, and a DMARC record. If your domain is with us, you set these up through DNS management in My Domains. Start with DMARC using p=none and tighten it step by step, see What is DMARC? Explained in plain language.