Discover the secrets to better email delivery and increased deliverability rates. Fix potential issues and enhance your email marketing reputation.
December 12, 2023
Navigating Email Deliverability: From Basics to Best Practices
In this article, we will delve into the complexities of deliverability, exploring why even the most well-crafted emails can fail to reach their intended destinations and how to improve email deliverability. It’s important to note that the terms “email deliverability” and “email delivery rate, ” though frequently used interchangeably within email marketing, have distinct differences — let’s begin by taking a closer look at both of these concepts.
What is Email Delivery?
Email delivery, simply put, is the rate at which emails successfully arrive at the recipient’s mail server. The delivery rate (DR) can be calculated using the following formula:
For example, if a company sends out emails to 100 clients and 55 emails land in the inbox, 25 in the promotions tab, 4 in the spam folder, and 16 bounce back, then the delivery rate would be:
Today, Email Service Providers (ESPs) and platforms have largely automated the calculation of the delivery rate, integrating this metric into campaign reports for efficiency and insights. A good benchmark for the email delivery rate is 95% — anything less suggests there is a problem that needs to be identified and resolved.
What is Email Deliverability?
Indirect indicators such as the open rate and click rate can hint at deliverability issues. For instance, if the delivery rate remains high at 99% but there is an unexpected dip in these engagement metrics, it could suggest that a larger portion of emails is being filtered into spam than usual.
Email Delivery Rate vs Email Deliverability
In essence, delivery merely confirms that an email has been received by the recipient’s email server, whereas deliverability dives deeper, gauging an email’s ability to pass through all the filters and barriers set up to protect users from unsolicited emails — this makes the email delivery rate a crucial benchmark in evaluating deliverability.
Why Does Email Deliverability Matter?
Email deliverability is vital to the success of your email marketing campaigns. It affects the visibility of your messages, shapes your sender reputation, and directly influences recipient engagement — let’s explore how deliverability impacts these crucial areas.
Direct Impact on Visibility
Deliverability determines your email content’s visibility. When emails fail to reach the inbox, the intended message remains unseen, and the potential for customer engagement and conversion is lost. This invisibility undermines the very purpose of email marketing and can render the resources dedicated to it obsolete.
Influence on Sender Reputation
The sender reputation is a score assigned to an email sender, used by Internet Service Providers (ISPs) and Email Service Providers (ESPs) to determine the trustworthiness of an email source. This reputation influences whether an email will be delivered to the inbox, spam folder, or blocked entirely. ISPs and ESPs monitor how emails from a sender are received and treated by recipients. High rates of emails marked as spam or left unopened can damage this reputation, causing future communications to be directly filtered into spam folders or blocked. Sustained deliverability is key to maintaining a positive sender reputation.
Improved Engagement Metrics
Emails that successfully land in the inbox are more likely to be opened and engaged with. High deliverability rates correlate with higher open and click-through rates, leading to more effective campaigns. This engagement not only achieves immediate campaign goals but also helps increase email sender reputation, creating a reinforcing loop that supports future deliverability.
3 Factors That Affect Email Deliverability
While there are numerous issues that can impact email deliverability, they can all generally be grouped into three main buckets:
1. Sender Reputation and Email Authentication
- Email volume: Sudden spikes or irregular sending patterns can raise red flags. Consistent email volume is seen as more reliable.
- Bounce rates: A high number of bounced emails (emails that fail to be delivered) can negatively impact reputation, so keeping bounce rates low is crucial.
- Spam complaints: If recipients frequently mark emails as spam, this is a strong negative signal that lowers sender reputation.
- Engagement rates: Positive interactions with emails, such as opens, clicks, and forwards, indicate good sender reputation.
Coupled with this is email authentication, involving protocols like Sender Policy Framework (SPF), DomainKeys Identified Mail (DKIM), and Domain-Based Message Authentication, Reporting, and Conformance (DMARC) – more on these below. Together, the protocols work to verify the sender's identity and contribute to a positive reputation, which is essential for bypassing spam filters.
2. Legal Compliance
- Using honest headers where the “From, ” “To, ” “Reply-To, ” and routing information accurately identify the person or business who initiated the email.
- Using subject lines that reflect the content of the email.
- If the email is an advertisement, this should be clearly disclosed — for instance, using language that unmistakably indicates its promotional nature. An example of a subject line that does this could be: "Summer Sale: 40% Off Our Entire Collection."
- Including a valid physical postal address for the sender.
- Providing a clear and easy method for recipients to unsubscribe from future emails, and promptly honoring these requests.
3. Email Content Quality
In addition, an email with too many images or images that are too large can not only affect loading times but also raise flags with spam filters.
How to Improve Your Email Deliverability
Improve the Quality of Your Subscriber Base
- Removing invalid addresses that contain errors or consistently fail to receive emails. Manually checking the validity of each address is time-consuming, so many businesses use email validators. These services can automatically remove nonexistent addresses, duplicates, and improperly formatted addresses from the database. They can also provide reports or prepare lists for SMTP (Simple Mail Transfer Protocol) or FTP (File Transfer Protocol) servers for distribution. The cost of such services generally depends on the number of addresses in your database, with larger databases often benefiting from lower costs per address verification.
- Incorporating a format validation step during email registration can prevent users from entering incorrect addresses.
For example, this brand rejects all customer email addresses if they lack an “@” symbol
- Routinely clean your database to remove email addresses that are no longer receiving emails. Advanced ESP platforms can automate this process by identifying and removing such addresses. Platforms like Maestra categorize these addresses into a global list and automatically exclude them from future email campaigns.
- Avoid purchasing or scraping email lists from the internet for your campaigns at all costs — these can be fraught with invalid or outdated addresses. Using such lists can not only harm your domain’s reputation but also increase the likelihood of degrading the overall effectiveness of your email deliverability.
Implement Double Opt-In
DOI also safeguards against spam traps set by email providers, which are special email addresses owned by the provider. Sending messages to these addresses can result in being blocklisted by email servers.
Configure Email Authentication Protocols
- SPF specifies which servers and IP addresses are authorized to send emails for your domain, thus confirming the email’s origin.
- DKIM provides an additional layer of verification, akin to a digital signature, ensuring the email has indeed been sent from the claimed domain.
- DMARC allows you to specify how to handle emails that fail SPF and DKIM checks — whether to reject them, mark them as spam, or deliver them to the inbox. Without DMARC, these decisions are left to the receiving email server. DMARC also compels the email server to send reports to the domain administrator about the sent emails and how these were treated by the email service.
Collectively, these protocols play a vital role in safeguarding your recipients from phishing attempts and enhancing the trustworthiness of your emails.
Segment Your Recipients
For instance, you can create segments based on factors like purchase history, style preferences, age, or a combination of multiple features for ultra-precise targeting. This will allow you to compose tailored emails that customers find relevant and even look forward to.
Create a Smooth Opt-Out Process
Implementing a one-click unsubscribe process is optimal. However, providing an optional feedback form for users who choose to unsubscribe can offer valuable insights. Understanding why subscribers choose to leave can help you refine your email strategy and improve future content.
Feedback forms can give you a better understanding of why customers unsubscribe from notifications and what you can do to improve their experience
Email Deliverability: Recap
Improving email deliverability is a continuous process. It involves adapting to evolving email practices, understanding recipient behavior, and leveraging technological advancements. When executed well, these efforts lead to improved campaign performance, stronger audience relationships, and a higher return on investment in email marketing.