1. What Is DNS?
When looking at email deliverability, one of the foundational areas we need to focus on is the proper setup of your Domain Name System(DNS) records.
Here’s why DNS matters: At a basic level, when you send emails, there’s a machine-to-machine communication happening between your sending platforms and the receiving inboxes. This system uses checks and balances to ensure you are who you say you are. It’s basically checking that the sender who claims to be sending the email is actually the real sender. This helps reduce phishing and spoofing attempts.
This system of communication also does something else important – it authenticates the content of your messages. It makes sure that your email hasn’t been modified in transit or corrupted in any way. This basic level of security happens during the back-and-forth communication between machines and relies on DNS records and proper setup of authentication records within your DNS hosting.
Now, let’s take a step back – what exactly is DNS? DNS stands for Domain Name System, and it exists as records on your hosting platform. This could be on GoDaddy, Cloudflare, or wherever you host your website and other infrastructure-level items for your web activities.
When we talk about records related to email deliverability and authentication, there are three crucial records you need to know about and set up correctly:
- SPF records
- DKIM records
- DMARC records
While there are other records that play a role too, these three are the most important ones you need to get right.
2. What Is An SPF(Sender Policy Framework)?
An SPF Record (Sender Policy Framework) is a DNS-level record that you place on your hosting domain to help with email authentication, which impacts your email deliverability. When you put this record on your Domain Name System, you’re basically indicating which IP addresses are allowed to send emails on behalf of your domain. These are the authorized IP addresses that you put inside the record.
When receiving inboxes get email messages from these IP addresses, they check if you’ve authorized them to send on your behalf. If you have, the email passes SPF authentication checks and gets through the first filter.
To configure SPF records, search Google using the query: “SPF record setup [hosting/DNS provider]” (e.g., Cloudflare, Google Workspace, GoDaddy, Namecheap, AWS Route 53).
3. What Is DMARC (Domain-based Message Authentication)?
The main function of a DMARC record is to let you, as a sender, set a policy for receiving inboxes to follow when they get emails claiming to be from you that fail authentication. Think of it as a tool that lets you tell inboxes like Gmail and Yahoo what to do when someone tries to spoof your emails or send other non-legitimate mail pretending to be you.
To configure DMARC records, search Google using the query: “DMARC record setup [hosting/DNS provider]” (e.g., Cloudflare, Google Workspace, GoDaddy, Namecheap, AWS Route 53).
4. What Is DKIM (DomainKeys Identified Mail)?
DKIM, along with SPF and DMARC, is part of the trio of email authentication protocols that help your emails reach receiving inboxes properly. These three protocols work together to:
- Authenticate your mail
- Ensure it aligns with who you are as a sender
- Make sure message contents haven’t been modified during transport
DKIM specifically handles that last part – making sure the content hasn’t been corrupted between when you send it and when the receiving email provider gets it. While it’s primarily a security mechanism, it greatly affects deliverability. If you fail DKIM authentication, your emails will likely be rejected or quarantined, never reaching your subscribers.
To configure DKIM records, search Google using the query: “DKIM record setup [hosting/DNS provider]” (e.g., Cloudflare, Google Workspace, GoDaddy, Namecheap, AWS Route 53)
5. Feedback Loop (FBL)
A feedback loop is an ISP service that notifies recipients when an email is marked as spam. This information helps senders maintain clean lists and improve email quality.
When receiving a complaint via FBL, senders should:
- Remove the recipient from the list
- Assess the frequency and content of the issue
- Use the information to understand recipient behavior
To register for FBL, you need:
- Own an IP or domain
- Have an abuse@ or postmaster@ address
- The IP’s DNS must match the domain
- Have a good reputation
Most major ISPs offer FBL. Many ESPs handle this automatically.
6. Choosing an ISP and ESP (Email Service Provider)
When choosing an email service provider, consider:
- Average deliverability rate
- Shared IP policy
- Experience and reputation in the industry
Premium ESPs typically have better deliverability rates. M3AAWG and SendGrid are examples of “white hat senders” who have transparent relationships with their ISPs and good tech support.
Even if you follow all the rules, a poor quality ESP can still impact deliverability. Periodically review your ESP and consider upgrading as your email marketing needs increase.