Email Deliverability Essentials: How to Ensure Your Emails Reach Inboxes

The email deliverability rate across major email service providers is 83.1% on average. This means nearly 1 in 6 marketing emails still fail to reach the inbox. More specifically, 10.5% of emails end up in spam folders, while 6.4% disappear entirely. 

Most users and business owners acknowledge the importance of email deliverability; 78.5% of survey respondents rated its importance as 8 out of 10 or even higher. However, there are still some significant gaps in implementation, 70% of senders do not use tools for monitoring their sender reputation, and 53% do not actively monitor email blocklists. 

Email authentication protocols are very important for boosting email deliverability. In fact, recent data shows a 45% adoption rate for DMARC, which was previously only 37% in 2024. In this article, we delve into the essentials of email deliverability and show why email authentication protocols are so crucial in helping your messages reach the intended audience. 

But Why Is Email Deliverability So Important?

In case emails from a company fall into the spam folder more than once, over 52.7% of consumers mention that they either find themselves displeased and frustrated, their trust in and respect for the company gets eroded, or, what’s worse, they unsubscribe. 

While 70% of users search their spam for important emails, nearly 30% don’t, which means that a significant percentage of your client base might not even see (let alone open) your email if it falls into the spam folder. Additionally, out of those who do check their spam from time to time for missing emails, nearly 33% of them get annoyed and frustrated when they see emails from a given company in the spam folder and not their inbox. 

Such statistics and customer complaints were perhaps some of the driving forces that contributed to improved email deliverability rates over the past few years. In fact, between 2020 and 2023 alone, so just in three years, the average deliverability rate rose from 94.26% to 96.43%. Especially those businesses that operated in the e-commerce industry started paying more attention to deliverability rates, which experienced the largest improvement among all sectors (a rise of nearly 10.28% rise).  The spam rate was also reduced by 44.4% in 2023 in comparison with 2020. Due to the improvements in email deliverability and reductions in spam, the average unsubscribe rate was brought down significantly in just 4 years, seeing a 26.32% decrease. 

Email Authentication Essentials

Before we delve deeper into how email authentication protocols can help you increase your email deliverability, we should first understand what email authentication is and why is it important.

1. Email Authentication Protocols 

Email authentication refers to the process of checking the legitimacy of your emails by verifying whether or not they come from an authorized, legitimate source associated with your domain. Email authentication helps ensure that all Mail Transfer Agents (MTA) who can send or alter emails from your domain’s behalf have the appropriate domain registrant and control verification. 

SPF, DKIM, and DMARC

Now that you understand what email authentication is and what it’s for, let’s explore how you can leverage email authentication protocols for better email deliverability. 

SPF:

SPF (Sender Policy Framework) is an important email authentication method implemented through DNS TXT records. It helps define a list of authorized IP addresses and servers that are permitted to send emails on behalf of your domain. When an email is dispatched from your domain, it includes the IP address of the sending server and your domain’s email service provider. This information is stored in your DNS as an SPF record, which can be created using an SPF generator to ensure accuracy.

When receiving an email, the recipient’s mail server conducts a verification process. It checks the sender’s IP address against the SPF record associated with the sending domain. Based on this check, the email is marked as either SPF pass or fail to prevent email spoofing and other forms of unauthorized, malicious use. 

Please note that there is a 10 DNS lookup limit, and in case you do not respect this limit, you might face PermError and SPF failure. Using tools like Hosted SPF will ensure compliance with this requirement and prevent any issues like SPF failures. 

DKIM:

DKIM is the standard email authentication protocol that makes use of a private key to assign a cryptographic signature for validating emails in the server of the receiver. The receiver can access the public key from the DNS of the sender. This process helps to check the legitimacy and authenticity of all incoming emails.

DKIM public key, like SPF, is stored in the DNS of the domain owner in the form of a TXT record. The recipient’s server can then use the public key to ‘decipher’ the DKIM signature and understand whether or not the email has been manipulated in the transmission process. 

DMARC:

DMARC (Domain-based Message Authentication, Reporting, and Conformance) is currently the most widely used and one of the most important components of email authentication. 

When you add a DMARC record to your domain’s DNS, it acts as a useful mechanism to ask the recipients’ servers to give feedback about emails sent on behalf of your domain. Not only does this provide you with better and more detailed insights into the emails you send but also helps indicate to receiving servers that your secure email protocols such as DMARC, SPF, and DKIM are fully supported by your domain. 

DMARC as A Cornerstone to Better Email Deliverability:

DMARC aggregate reports let business owners examine their email authentication outcomes, find any failures related to configuration or authentication, and solve any problems that might have jeopardized their email deliverability rates. Through a comprehensive and well-devised DMARC policy, it is much easier, faster, and more cost-effective to stop hackers from sending dangerous emails on your behalf that could have put your brand image and reputation in question. 

2. IP & Domain Reputation 

IP reputation refers to the score that is assigned to the IP address that is used to send emails. The score is usually based on past sending behavior and is influenced by several factors, including spam complaints, email engagement rates, and bounce rates, as well as sending volume consistency. 

A good IP reputation can help boost email deliverability, while a bad one can lead to spam. Domain reputation, on the other hand, relates to the overall “health” of your email domain for mailbox providers, and email authentication protocols like SPF, DKIM, and DMARC can positively affect your email reputation and deliverability. A good domain reputation indicates to Internet Service Providers that your domain sends safe, legitimate emails. 

3. Email List Hygiene 

Maintaining good email hygiene refers to the practice of cleaning out inactive email subscribers from your next email marketing campaigns while also ensuring those who stay are engaging with your emails.

4. Content and Sending Practices 

Paying attention to your content can help you with the above two points as well. Interesting, informative, engaging, and reliable content can help you ‘warm up’ your recipients, preventing them from becoming cold or inactive. It can also improve your domain reputation and decrease the likelihood of spam. Also, pay attention to your sending practices, ensuring you don’t bombard your audience with emails. Sometimes, pushing too hard can push people away!

5. Engagement and Bounce Management 

Engagement metrics (e.g. open rates, click-through rates, reply rates) can directly impact your email deliverability. In fact, high engagement indicates to Internet Service Providers that your emails are relevant to and welcomed by your audience. Good engagement rates can help boost sender reputation and email deliverability, reduce spam, and result in better inbox placement. High bounce rates, on the other hand, negatively impact the sender's reputation and can often result in blacklisting.

The Impact of Email Authentication on Deliverability

When you implement SPF, DKIM, and DMARC correctly and effectively, it can significantly improve your email deliverability. This is because: 

• Emails that pass SPF and DKIM checks are more likely to be delivered to the inbox rather than the spam folder.
• DMARC implementation can lead to a reduction in email spoofing attempts and thereby help protect your brand reputation and boost deliverability.
• Domains that have DMARC policies in place witnessed a 23% increase in email deliverability rates in comparison with those without DMARC.
• Making use of hosted BIMI services can make it easier for your recipients to recognize your brand and thereby increase email open rates. 
• You can also solve email delivery problems with the help of extensive security reporting mechanisms like TLS-RPT and ensure safer email transmissions with the help of MTA-STS.

Summing Up 

Remember, boosting email deliverability is not about one single magic formula or cookie-cutter approach; instead, it is the result of several effective measures and mechanisms that often need to be implemented together to reach the intended outcome.