For some of you, the term “DNS” surely evokes something vague, or even ultra-technical, better left to the experts. Yet, this famous DNS is like the GPS of your emails. A wrong setting, and your messages, even the best designed, may get lost along the way. In this article, we explain the impact of DNS on deliverability and especially how to configure it simply and effectively.
What is the main role of DNS at the email level?
DNS, or Domain Name System, is a tool that translates an internet domain name into an IP address. It acts as an online directory that links your domain name to the technical information necessary for sending emails.
For example, when someone types an address like “captainverify.com” in their browser or receives an email from this domain, DNS tells the servers where to find the website.
In the context of emailing, its main role is to authenticate your messages and indicate to mailboxes whether your emails are legitimate or suspicious. In other words, it proves that you are indeed the sender.
Three types of DNS records are essential for this:
- SPF which indicates the servers authorized to send emails from your domain.
- DKIM which adds a digital signature to your emails, ensuring that the content has not been altered in transit.
- DMARC which centralizes SPF and DKIM, and gives instructions (quarantine, rejection) to mailboxes in case of a problem. It also includes a reporting system to monitor fraud attempts.
How DNS directly influences the deliverability of your emails
First of all, DNS reassures email service providers. When you send an email, they check that your domain has the correct SPF and DKIM records. These verifications have become a basic condition for accepting a message. If these elements are missing or misconfigured, your emails are likely to be blocked or placed in spam.
Then, DNS protects your brand against impersonation. Without DMARC, anyone can attempt to send emails pretending to be you; this is what is called ” spoofing ” and the consequences can be quite serious. DMARC therefore acts as a shield by preventing these fraudulent sendings and preserving your reputation.
Finally, DNS gives you a good overview of the actual usage of your domain for sending emails, whether by you or someone else. DMARC generates regular reports that allow you to monitor sending sources (internal or external), and correct vulnerabilities.
Best practices to know
To give your emails the best chance of arriving, here are the DNS points to check:
- Use DKIM keys of at least 2048 bits, and consider renewing them every 6 to 12 months to minimize risks if a key is compromised.
- Limit “includes.” These instructions allow platforms to send emails on your behalf, but overusing them increases complexity and can cause errors.
- Deploy DMARC gradually without blocking everything at once. Start with p=none, then analyze the reports, gradually increasing security (“quarantine” or “reject”). This way, you advance step by step without risking accidentally blocking legitimate emails.
- Think about BIMI. When DMARC is well-configured, you can display your logo in the inbox. It’s a good way to strengthen trust.
DNS configuration for optimal deliverability
No need to be a computer expert to grasp the basics of good DNS configuration. Here’s a simple, step-by-step method to prevent your emails from landing in spam or being blocked by mail systems.
1) List the tools used to send emails
First of all, identify all the services that send emails on your behalf. This includes your emailing platform, your website, your customer relationship management software (CRM), etc. By doing so, you will avoid missing one in the configuration, which could block certain sendings.
2) Authorize the right tools with SPF
SPF allows you to indicate to mailboxes the services authorized to send messages for you. Simply add a small text to the settings of your domain.
Simple example: v=spf1 include:myprovider.com -all
Make sure there is only one SPF record for your domain, and that all your sending tools are included.
3) Ensure that your emails are correctly signed with DKIM
No need for coding here, your email service generally provides the instructions. You just have to copy-paste a piece of information (called a “key”) into your DNS interface. Then, test an email with a free tool like Dkimvalidator to ensure everything works.
4) Activate DMARC to better protect your domain
As advised above, start simple, without blocking emails:
v=DMARC1; p=none; rua=mailto:youremail@yourdomain.com
You will receive reports telling you if your sendings are well-configured or if there are fraud attempts.
After that, you can strengthen security:
“quarantine”: suspicious emails go to spam.
“reject”: suspicious emails are blocked.
5) Check that everything works
Once everything is in place, take a few minutes to do a complete test using a tool for verifying DNS configuration, like DNS Checker, MxToolbox, or IntoDNS.
These will tell you if your settings are correct or if an adjustment is necessary.
DNS is an essential part of your email strategy. Take the time to set up SPF, DKIM, DMARC, try BIMI, and establish tracking. By doing this, you will enhance the reliability of your sendings and protect your brand.
One last thing on the road: the technique is not everything. Also, take care of the marketing aspect (content, timing, segmentation) as the two go hand in hand for foolproof deliverability.
