
Email Deliverability and How it Works

DNS, SPF, DKIM, DMARC, domain reputation, IP reputation, copy, and content are all factors in whether your email reaches the recipient’s inbox. Spam filters have gotten smart enough to determine that I like receiving a certain message, but you hate it. To fully grasp the concept of deliverability, it's essential to dive into the plumbing of email security.
DNS (Domain Name System)
DNS (Domain Name System) is a critical component of email infrastructure that helps route and authenticate email messages. Properly configuring your DNS can impact whether your emails reach their intended recipients or end up in spam folders. DNS is an integral part of email authentication, as it stores the essential records required for SPF, DKIM, and DMARC. These mechanisms, when implemented properly, enhance the trustworthiness of email communication by validating the authenticity of the sender's domain. The DNS is used to perform reverse DNS lookups for further verification and also to inform receiving servers of if your domain or IP address is listed on any blacklists. It's essential to monitor your domain and IP reputation and take action to delist if you find yourself on any blacklists.
Domain and IP reputation are used by email service providers and spam filters to measure the trustworthiness of domains and IP addresses. It's important to understand the factors that impact them as well as how they differ. Both domain and IP reputation are dynamic and can change over time based on the sender’s behavior and the recipient’s feedback.
Domain Reputation
Domain reputation centers on the trustworthiness of the domain from which the email originates. This domain corresponds to the “From” address displayed in the email header. Domain reputation hinges significantly on the presence of email authentication protocols, such as SPF, DKIM, and DMARC. The correct configuration of these records can substantially enhance the standing of the sending domain. Moreover, domain reputation is intricately tied to the domain’s sending history. This includes aspects like email volume, sending frequency, and the consistency of sending patterns.
Along with sending history, domain reputation also places significant weight on the quality of content and recipient engagement. High-quality content tends to yield positive engagement metrics, including elevated open and click-through rates, which help bolster the domain’s reputation. Conversely, the quality of email content can help minimize instances of recipients marking emails as spam. Accumulating user complaints is a surefire way to get added to one of these blacklists which can cause deliverability to take a dive. Unlike IP reputation, your domain reputation is transferable. That means you could add new IP's or move IP's, and you'd still enjoy the benefits of a good domain reputation.
IP and domain reputation are interconnected aspects of email deliverability. While they share some common elements, they have distinct focuses and characteristics.
IP Reputation
IP reputation primarily revolves around the behavior and reputation of the specific IP address used for sending emails. It's more about "how" emails are sent versus "who" is sending them. IP reputation is also affected by sending behavior, authentication, and user complaints. A key difference, however, is the presence of the IP address on any blacklists. If your campaigns are constantly assessed as spammy, your IP address could end up on one of these blacklists. Being on a blacklist can have negative impacts on email deliverability, so it's important to monitor these blacklists for any IP addresses that you use.
Both domain reputation and IP reputation play crucial roles in email deliverability. A strong sender reputation requires maintaining positive reputations for both the sending domain and IP address. Hopefully this has given you a better understanding of the inner workings of DNS, domain reputation, and IP reputation. Next we're going to dive into how copy and content can help you reach the inbox.
Copy and Content
"Copy" typically refers to the written text or the message content of an email. It encompasses the subject line, the body of the email, headlines, subheadings, and call-to-action (CTA) text. "Content" encompasses all elements within an email message, including the copy, images, links, HTML structure, design, and other multimedia components. Content also includes attachments, if any.
While copy itself does not directly impact deliverability, the quality of copy can influence recipient engagement and user behavior. Engaging and relevant copy is more likely to lead to higher open rates, click-through rates, and lower spam complaints.
The content of an email has a more direct influence on deliverability than copy. Issues with the email’s content, such as image-to-text ratio, broken links, improperly formatted HTML, can result in email deliverability problems. For example, an email with a high image-to-text ratio or links to blacklisted domains can be flagged as spam.
While copy quality indirectly affects engagement and, therefore, deliverability, content quality is more directly tied to email deliverability. Issues within the content can trigger spam filters and result in email placement issues. Both copy and content should be carefully crafted and reviewed to ensure successful email marketing campaigns.