Reverse DNS White Labeling — Hello, My Name Is…

DNS is about as old as the internet itself, and it’s easy to understand why. Domain names are way easier to memorize and remember than IP addresses, so DNS records were bound to catch on as more and more people started using the internet. Could you imagine remembering each IP address of the sites you wish to visit? That’d be a handful.

However, DNS isn’t only about translating domain names into IP addresses; it directs particular internet traffic like email and SIP voice/video, allows domain verification and ownership, and permits senders like Mailgun to send on behalf of their customers. When we talk about DNS, we often want to look at how it affects your email, like your domain and IP reputations.

Here at Mailgun, we can create IP addresses for dedicated sending, and those IP addresses resolve in reverse to hostnames at a domain that belongs to us. Now, what if we told you there is a way to set up reverse DNS records for your dedicated IPs to make it look like you’re sending from yourself directly, rather than from Mailgun?

Wait, really?

Yes, we have the ability to create custom pointer (PTR) records for you so that the rDNS record of a connecting IP is representative of the message. Everything still sends the same, it just looks like it’s coming from you directly rather than through a service like Mailgun. We covered something similar before with masking the CNAME of mailgun.org in your DNS, but this is a bit different. In this instance, we’re only talking about the reverse DNS of your dedicated IP for sending.

For example, a rDNS record of m123-456.mailgun.net is representative of a message coming from Mailgun, but a rDNS entry of m123-456.customer.com will show the sender as coming from you to inbox providers.

It’s important to note that this cannot be done with shared IPs since it can only resolve for one hostname. However, if you’re using a dedicated IP it adds a nice added polish to your messages, and it doesn’t hurt with inbox providers either if you have a good reputation.

Interested?

We’ve got everything you need to make this happen. Mailgun will provide you with an A record that you then input into your zone file at your hosting provider. An A record will look something like this.

A, mail.customer.com, 123.45.67.89

That takes care of the forward portion for the IP, but we also need to update the PTR record on our end to match the hostname the customer used. In order to do that, just submit a ticket to our Support Team, and we’ll take care of the rest.