What is email deliverability? Definition and tips for improving your rate

If you’re struggling with high bounce rates, unresponsive lists, and other email deliverability problems, you might be desperate for answers. When you Google “what is email deliverability?” or “how do I improve deliverability?” most results are filled with jargon and vague answers. And much of the pseudo-advice you get boils down to, “It’s complicated. It depends.”

We’re here to cut through the noise and give you an answer once and for all. With this guide, you’ll learn what email deliverability is and how you can improve it for your own email marketing campaigns. By using a few simple tricks and the right email marketing software, you can ensure your messages actually make it to your subscribers’ inboxes.

What is email deliverability?

At its most basic, email deliverability is what measures the chances of your emails making it to your recipients’ inboxes. Sounds simple enough; however, there are many obstacles that stand in the way.

Email deliverability and IP reputation are complex and can change from day to day or even hour to hour—even when sending emails to the same list on the same platform. There’s no silver bullet to “fix” overall deliverability because Email Service Providers (aka ESPs like Gmail and Outlook) are constantly changing the rules for what gets delivered and what skips the inbox. Even your niche itself, along with your products or services, could affect your email deliverability rates.

For example, if your email deliverability rate is 80%, that means around 20% of your emails never make it to their intended recipients. Over the course of an entire email campaign, that’s a lot of lost messages and missed opportunities.

Not to worry, though. You can maintain healthy email deliverability by taking a few simple steps and using top-of-the-line tools, which we’ll cover below.

8 tips for improving email deliverability

We’ll walk you through tips you can use, and features built into the Kajabi platform that should help improve your email deliverability rate. From the moment you draft your email, to the moment it reaches your recipient’s inbox (if it does), a series of filters analyze your message for potential spam. It takes care from beginning to end to ensure your emails reach customers’ inboxes, but it’s worth it.

1. Avoid spam triggers in your copy

The content in your subject lines and body can contain possible spam triggers that affect your email deliverability. You’ll want to avoid using words and phrases that sound, well, spammy. Some examples that are known to trigger spam detectors include “free cash”, “extra income”, or “save $”. Additionally, you should refrain from overuse of punctuation like “!!!” and writing in all caps.

Using the new Kajabi Email editor, you control the design and text of the subject line, preview text, and body. Our smart system checks your email for spam triggers using:

• Subject line validation, which checks for potential spam triggers as you’re typing. If it detects a trigger, it will suggest exactly what to fix.
• Backend email spam service, which evaluates your body content before sending. Any content that’s especially egregious gets flagged and rejected from being sent. This happens very rarely.

2. Maintain good email list hygiene

While it may feel beneficial to cast as wide a net as possible and email as many recipients as possible, when it comes to email deliverability, you need to account for the quality of your audience.

Quality over quantity wins, any day of the week.

In the ideal scenario, you’re sending emails only to the contacts who interact with them. The more your recipients open, click, reply, and forward your emails, the more solid your reputation will be.

Ensuring high audience interaction is all about maintaining email list hygiene. Ultimately, the better you maintain your email lists, the better your email deliverability will be.

To ensure a healthy email list from the start, use Kajabi email capabilities like a double opt-in, where a recipient is asked to take a secondary action in a confirmation email to verify they actually want to be engaged via email. You can also unsubscribe and remove inactive contacts and emails that are permanently bouncing. (Your email automatically includes an opt-out to comply with anti-spam laws.)

You can also take advantage of email address validation, which sifts through potential subscribers and alerts you to recipients who could be harmful to your email deliverability. For example, a “high risk” subscriber could be someone using a domain in their email address that has been undeliverable in the past.

3. Use a consistent delivery schedule

One of the easiest ways to protect your email deliverability is to deliver your emails on a consistent and predictable schedule. Not only does this reduce email spikes, which can be red flags to some ESPs, but also helps your subscribers become familiar with your sending patterns. If a subscriber knows you send out a “Weekend Coupon” email every Friday at 3 pm, they’re more likely to look for, open, and engage with that email when they’re ready to make a purchase.

Our email delivery platform’s cloud-based infrastructure scales with growing businesses and stands out from other ESPs because it’s state-of-the-art. More than 150,000 companies worldwide—including Shopify, Slack, and Lyft—use our email delivery platform.

Using our Lightning Broadcast technology, Kajabi splits emails going to big recipient lists into separate chunks of 1000 recipients each. This helps rapidly speed up email delivery to our email delivery platform so that your emails arrive on time, every time.

4. Look for an email tool with deliverability optimization features

After you hit “Send,” many processes—which are largely out of your control—take place. Before reaching your recipients’ inbox, there are many obstacles your email must pass through. Even though you can’t manually control how your email performs at these checkpoints, you can opt for a tool that can optimize your email deliverability with features designed to give your messages their best chance at reaching the inbox.

Sophisticated technologies execute email delivery processes in ways that aren’t always clear-cut. The best way to describe these protocols is a pot bubbling with different ingredients. At Kajabi, we’re working on implementing certain features like email throttling, suppression lists, inbox placement, send-time optimization, and various other ways to warm up IP addresses. These protocols are constantly analyzing emails and how to place them in inboxes at optimal times.

For example, email throttling within our email delivery platform controls the number of emails sent to one ISP or remote server at one time. Without mechanisms to control how quickly emails get released, the emails are more likely to inundate ISPs and trigger them to flag as spam.

Suppression lists are another feature that helps improve email deliverability. Let’s say a recipient's address is invalid, either because the domain name is incorrect, isn't real, or the recipient is unknown. The email will hard bounce every single time. Remember, we’re looking for the highest rate of audience interaction to boost reputation and email deliverability—bounced emails will count against that. Our email delivery platform will automatically filter out those emails by putting them on a suppression list so they present less of a threat to your deliverability rates.

5. Send from reputable domains and IP addresses

In the world of email deliverability, the reputation of the sending domain and sending IP address has a big influence on whether messages make it to the inbox. If you’re sending from an IP or domain that has little to no reputation, you’ll need to “warm-up” your recipients’ ESPs before they fully trust you as a sender. Start by sending just a few emails at a time and slowly increase the number over time.  

If you’re sending from an IP or domain with a bad reputation, you’ll need to be especially cautious about what you send and to whom. Avoid language that sounds spammy and make sure your lists are clean. Try to only send to contacts who are very likely to open your emails.

At Kajabi, all users get the benefit of reputable shared domains and shared IPs. If you’re a new business or don’t send high volumes frequently, you can leverage Kajabi’s elevated sender reputation.

For the high-volume, high-frequency senders with high engagement rates and low bounce rates, Kajabi is exploring the possibility of offering additional premium features, such as dedicated IP addresses and custom sending domains so that you can keep the reputation you have already built. A dedicated IP address would provide greater control over one's IP reputation, although it would require much more proactive management than a shared IP.

Stay tuned for future updates as Kajabi continues expanding its email capabilities.

6. Get to know how different ESPs assess your emails

Keep in mind, that your email broadcast will likely go to a handful or a dozen different ESPs depending on your list, e.g. Gmail, Hotmail, Yahoo, and other providers. Every ESP has its own proprietary algorithm that’s constantly analyzing incoming emails. Never-ending changes to these search algorithms are inevitable as spammers discover loopholes and slip through spam filters.

When an email reaches an ESP and its many spam filters, Kajabi and its users don’t have much visibility of the ins and outs. We know that IP reputation plays a major role in the algorithm, but there are other factors that could be at play.

Here are a few common email deliverability factors an ESP could potentially assess:

• The ratio of images versus text (hint: try to follow the 80/20 rule: 80% text to 20% images)
• Previous engagement between the sender and specific recipient  
• Overall engagement from all recipients
• The “reply to” address and how it relates to the source domain
• Historical sending patterns
• IP/domain reputation
• Errors in the email’s code

Additionally, here’s a quick roundup of the security checks an ESP may perform help ensure the sender is who they claim to be:

• SPF. Sender Policy Framework checks the DNS record and prevents unauthorized sources from sending emails from your domain.
• DKIM. DomainKeys Identified Mail uses public-key cryptography.
• DMARC. Domain-based Message Authentication, Reporting, and Conformance tells the receiver what to do if an email does not pass SPF or DKIM authentication. DMARC setup can help improve your email deliverability.

What happens to an email that’s flagged as spam has a lot to do with the ESP who is handling that email. One provider might hold spam in a junk mail folder. Another provider might give the message a spam header. And yet another provider might allow the recipient to block individual email addresses entirely. In that scenario, all future emails from that sender would skip the inbox completely and go straight into the trash bin before the recipient sees it.

If you notice an uptick in the number of spam reports for a particular ESP, use it as an opportunity to improve your emails. Try A/B testing your emails to optimize for deliverability (e.g. try using fewer images) and monitor their performance with that ESP on your next send.

7. Understand how native apps respond differently

Whether your recipient is checking their email through a web browser like Chrome or Safari or a native app like Apple Mail or Microsoft Outlook, the difference poses another variable. Native apps typically perform their own level of spam detection. For example, one native app might consider a message safe if the sender is in the address book, while another app might follow a different rule.

Bounces get automatically reported back to our email delivery platform and Kajabi, and ultimately back to you as the sender. This, of course, is important information that can help you maintain a higher-quality email list. You can try A/B testing your emails if you notice deliverability decreasing with a particular app.

8. Learn how your recipients engage with your emails

Assuming the email survives spam detection from the ESP and native app, it then lands in the recipient’s inbox. Now your recipient has control. If the subject line is forgettable or undesirable, your recipient is more likely to scroll past or delete it. In that case, the journey ends there.

On the other hand, let’s say your recipient opens the email. Again, what happens next depends on your recipient. Has your email message aroused curiosity about an offer? Has your email offered an irresistible freebie they can download? Or did something in the email annoy them enough to unsubscribe?

Whichever way your recipient responds makes its way back to our email delivery platform, Kajabi, and back to you as the sender. You now have valuable information to help you understand both how your email performs and how interactive your audience is.

And finally, the email’s journey comes to an end.

What’s the best thing you can do to improve email deliverability?

Email deliverability may seem daunting with many unknowns. However, in addition to using Kajabi’s industry-leading email feature, there are key steps you can take to help ensure your emails get delivered.

We can’t emphasize this enough; clean up your email list. This is perhaps one of the factors you have the most control over, and it’s a big one.  Do everything you can to make sure your recipients want to get your emails, and that they will actually interact with them.

Repeat this to yourself (and then actually do it): I will clean up my email list.

Now that you know what email deliverability is and how to improve your rates, it’s time to craft and send your own messages with Kajabi Email. Check out our guide on Email Best Practices to learn how to create engaging and high-converting emails.

For even more about Kajabi Email, check out:

Upgraded Kajabi Email: Your Questions, Answered!

Kajabi Email Deep Dive Training

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