How Important Your Email Deliverability Is And How to Improve It
Every business that uses email marketing relies upon it for nurturing leads, promoting campaigns, and driving sales. Email is a vital channel for fostering trust and elevating brand value through consistency. The scope of email marketing is vast, with global revenue projected to reach $17.9 billion by 2027. However, this revenue and success depend on a critical factor: email deliverability.
Many businesses confuse deliverability with plain delivery, which can cause their marketing strategies to fail. Email deliverability is defined as the rate at which emails sent from the server successfully reach the recipient’s priority inbox. Without an appropriate strategy, emails may land in the spam folder or get bounced, making it essential to have a high deliverability rate to achieve campaign goals. In this article, we’ll show you how important your email deliverability is and how you can improve it.
The Critical Role of Email Authentication and Reputation
Email authentication and domain reputation are central to ensuring messages reach their intended destination.
1. Building Trust and Preventing Spam
Email service providers (ESPs) scan incoming emails before sending them to recipients. If emails are unauthenticated, they are usually classified as fraudulent or phishing and immediately placed in the spam folder, or, in the worst-case scenario, blocked from entering the recipient’s server entirely.
Authenticating your emails builds trust and brand reputation. Since customers are wary of suspicious emails, authenticated messages boost confidence, ensuring customers are less likely to mark them as spam, which automatically helps drive the deliverability and customer retention rate higher. The sender score rated by the ISP (Internet Service Provider) plays a crucial role in determining the email’s deliverability, where a higher score increases the rate.
2. Essential Technical Authentication (SPF, DKIM, and DMARC)
Authenticating your domain ensures that emails are not perceived as spam.
• SPF and DKIM – These records identify which mail servers are authorized to send mail for your domain. SPF (Sender Policy Framework) helps prevent fraudulent sending by listing all authorized mail servers. DKIM (DomainKeys Identified Mail) allows receiving servers to sign and verify your email address as the sending domain. Both SPF and DKIM are mandatory.
• DMARC – DMARC (Domain-based Message Authentication, Reporting, and Conformance) is built on top of SPF and DKIM. It ensures proper authentication of your domain, and receiving servers execute the DMARC policy if authentication checks fail. Google, Microsoft, and Yahoo oblige senders to authenticate their domain with DMARC.
• DNS and TLS – You must ensure valid forward and reverse DNS records (PTR records) are set up to verify that the sending hostname is associated with the sending IP address. Furthermore, any email transmitted to Gmail or Yahoo must have secure TLS (Transport Layer Security) connections to encrypt emails for privacy and security.
3. IP Allocation: Shared vs. Private
The choice between a shared or private IP is key to influencing your sender reputation and control over campaigns. The IP address is one of the primary elements used by receiving mail servers to evaluate your trustworthiness.
• Shared IP is used by multiple senders simultaneously and is typically free or low-cost, but it comes with the reputation risk caused by other user’s sending behavior, as you share the IP reputation with them. Shared IP is already warmed up due to constant sending, and it’s best for beginners or low-volume senders.
• Private IP is used exclusively by one sender, so it often costs more, is available in premium plans or as an add-on. It gives full control over reputation, as only your sending behavior affects it. Private IP requires the sender to warm it up gradually and it’s the best choice for high-volume senders (more than 50,000 emails per month or at least one campaign per week).
Improving Deliverability Through List Hygiene and Quality
Even with strong authentication, a poor list can send legitimate emails to the spam folder. Here are a few things you can do to build and maintain a healthy and valuable email list.
1. Building a Clean List from the Start
• Build Your Own List: Buying an email list is illegal and will send your emails straight to spam, ruining your sender reputation. Building your own list, though slower, is more rewarding and ensures user engagement.
• Implement Double Opt-in: This is highly recommended to reduce bounce rate and ensure subscribers truly want the emails. It requires subscribers to confirm their sign-up by clicking a link, proving you are gaining a valuable lead and preventing bots from spamming sign-up forms.
• Use Quality Sign-up Forms: Forms should be simple and clear, and implement a good captcha system to prevent bots from entering invalid sign-ups.
2. Maintaining List Health and Reducing Bounce Rate
Email lists do not stay up-to-date forever, as contacts become invalid, inactive, or stale. There are a few things you can do to maintain a clean email list.
• Clean Regularly – If a list is old (more than six months), many addresses may have gone stale or been closed, leading to hard bounces (permanent delivery failure). You should clean your list by deleting inactive addresses and those that haven’t opened your emails for a long time.
• Avoid Role Addresses – Role addresses (like info@domain.com) should be avoided because they do not belong to a single person, are not intended for external marketing emails, and often become spam traps.
• Validation Tools and Confirmation Campaigns – Use advanced email validation tools to verify addresses before launching campaigns, which helps detect invalid, temporary, or role-based emails that could harm deliverability. For old, non-engaged lists, send a confirmation campaign to verify whether those addresses are still valid and if recipients still consent to remain on the list.
• Monitor Bounce Rate – The bounce rate (the percentage of delivery failures) should be kept as low as possible, with 2–5% considered a healthy and accessible range.
Email Strategy, Content, and Sending
The content of your email and adherence to legal requirements also heavily influence whether an ESP directs your message to the inbox or the junk folder.
Email content
First of all, your content needs to be relevant. Providing useful and desired content is essential for nurturing relationships, keeping subscribers engaged, and avoiding the spam folder.
Personalization
Another important aspect to take care of is email personalization, as it significantly increases user engagement. You can use custom fields and segmentation (e.g., based on recent purchases) to send more relevant emails.
Subject lines
You also need to curate compelling and actionable subject lines. Avoid “spam trigger words” or phrasing that sounds pushy, suspicious, or desperate in both the subject line and email body, as this increases the chance of landing in spam.
Sending timing and frequency
Remember that in email marketing, consistency is key. If you have a regular campaign agenda, subscribers and recipient servers know when to expect mail from you, ensuring better placement. AI-based models may help marketers predict the optimal time for sending emails to avoid the spam folder.
Email testing
And last but not least, always send test emails before deploying a campaign to check readability and ensure content loads correctly. Most email service providers offer email previews to see what a particular email will look like in the inbox. You can also use tools like Litmus or Email on Acid to check how your email will render on various devices and email clients. Using tools like Mail Tester can scan messages for spam content or malicious links and provide a spam score.
Legal Compliance
Compliance with anti-spam laws is mandatory. Marketers must ensure their processes comply with regulations like the CAN-SPAM Act of 2003, GDPR, or CASL. Crucially, you must provide recipients with an easy unsubscribe option in all marketing emails. When someone unsubscribes, they should be removed from the list within 2 days.
The Role of the Email Audit
Even successful marketers encounter challenges, and an audit is the answer to maintaining vigilance. An email audit is an in-depth evaluation of an email program, strategy, and supporting resources. The goal is to uncover technical issues and identify which strategies and tactics are effective versus those that need improvement.
1. When and Why to Audit
An audit should be conducted when taking over an existing account, when supervising a less experienced employee, or regularly (e.g., once a year) to check the health of the account and look for new ideas. Regular audits help identify major changes and trends over time.
2. Key Areas to Inspect During an Audit
• Essential Metrics – Check the open rate, click rate, unsubscribe rate, and bounce rate. Analyze long-term data (e.g., the past six months) to look for promising or concerning trends. The spam rate should be monitored in tools like Google Postmaster Tools and kept below 0.3% (ideally below 0.1%).
• Technical Integrity – Review DNS settings and verify that all crucial records, like SPF, DKIM, DMARC, and CNAME, are verified.
• Personalization and Content – Verify whether personalization is being used frequently and regularly, and look for better ways to segment the audience, for example, based on recent purchases. Pay attention to which emails (promotional or educational) perform best, and analyze the effective elements to implement them elsewhere.
• Automation and Compliance – Review all active email automations, including triggers and templates, as these can become outdated. Confirm that processes for lead collection (like double opt-in) and unsubscribing are running smoothly and comply with current legal regulations.
• External Tools – Use external tools like Google Postmaster or MXToolbox to assess your domain and email reputation. Also, test how emails render on different email clients like Yahoo, Outlook, or Gmail.
Email Deliverability – conclusion
The insights gained from this article hopefully provide numerous ideas and opportunities for improvement. Even small tweaks can significantly boost email deliverability, and consequently, email marketing results and increase generated revenue. However, it is vital to remember to always test your new ideas and changes identified during an audit, as potential improvements might inadvertently cause harm to crucial metrics.
Mastering email deliverability is like being a meticulous driver: you must perform regular inspections (audits) to ensure the technical components (authentication, IP) are sound and that you are driving safely (sending relevant, wanted content) to keep your vehicle (your email program) in good technical condition and reach your destination successfully.
