Everything You Need to Know About Email Deliverability

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Your email marketing campaigns are as good as your email deliverability rate. But, email deliverability is a tough nut to crack. This guide will share everything you need to know about email deliverability to send high-impact email campaigns.

Table of contents

What is email deliverability?

Email deliverability is the ability to deliver emails to your subscribers' inboxes. Marketers use deliverability metrics to measure email campaigns' likelihood to reach subscribers' inboxes and not the spam folders.

EmailToolTester found that the average email deliverability rate amongst all email service providers (ESP) was around 85.3%. The rest of the emails were either sent straight to the spam folder or blocked by the mailbox provider.

For future email campaigns, keep in mind these metrics and their baselines when you track your email deliverability:

  • A 95% or higher result is considered a good delivery rate on behalf of an ESP.

  • The bounce rate shouldn't be higher than 3%.

  • It would be best if you weren't ringing the alarm bells about the spam rate as long as it doesn't exceed 0.08%.

Most importantly, your email deliverability depends on the email marketing software you use for sending emails. Of course, every forum has different delivery rates. But, a reasonable email deliverability rate should be over 80% to 90% to enjoy the success metrics.

Difference between email delivery and email deliverability

There are a lot of misconceptions about Email delivery and deliverability, which are two different concepts. As an email begins its journey from the sender's server to the recipient's inbox, delivery and deliverability are two separate chronological events happening one after the other.

Email delivery Email deliverability
It tells you whether the email sent by you is received or not by the servers of your subscribers' inbox providers. If there is no bounce(inability to deliver to the servers), then the email count is taken as delivered. Email deliverability is the landing of an email in the inbox. The place of delivery differs based on the domain reputation, sender reputation, and domain setup. If there is an issue with any of these factors, your deliverability rate will face a massive hit.
Delivery rate = (Number of emails delivered sent / Number of emails sent) X 100 Deliverability rate = ( Number of emails delivered sent / Number of emails sent ) X 100

Why is email deliverability important?

In sales, the first step towards a successful pitch for a traveling salesman is to gain entry into the user's house. Similarly, while marketing via email, the first step toward getting ROI from email campaigns is to land in the end user's inbox.

1. Your email marketing success depends on successful deliverability

Email deliverability is the foundation for email marketing. As a primary step, marketers pay an ESP to send emails to them. Still, it's the marketer's responsibility to manage the email program and email list in the right way to ensure emails are landing in the subscriber's inbox or spam folder.

Marketers put so much effort and time into writing a perfect email copy and creating campaigns. But unfortunately, their effort goes in vain when the target audience does not open the sent emails because of poor deliverability.

Related guide: What is SMTP And How it Affects Email Deliverability

2. It can help you to be a winner in the inbox competition

Every business fights for its place in the consumer or client's inbox, and as a result, the email platform is very competitive. Everyone wants their emails to be read by leads and prospects and be far away from the spam folder. Good email deliverability helps you build a healthy relationship with the subscribers, which won't affect your email conversions and help you to stay ahead of the competition. Since reaching a consumer's inbox is an important growth metric, deliverability is a superpower for businesses.

Don’t be so elated if you see a higher delivery rate implying that your emails are not getting bounced. Even if emails are not getting bounced but landing in the spam folder then what’s the use of putting so much effort into creating an email? Lower inbox placement means lower email visibility and thus lower engagements and ultimately fewer conversions. Go beyond the delivery and bounce rate, and start tracking your email deliverability.

3. It helps you to study and understand user behavior

Email deliverability helps track the number of users opening your email, what time they have opened it, the number of active subscribers, etc. These insights are used by marketers to enhance user engagement and gather leads for better and improved email deliverability. Read how SBNRI improved their email deliverability with Mailmodo, leading to a 16% increase in open rates.

Challenges in measuring email deliverability rate

Measuring the email deliverability rate is challenging at present. Some measure email deliverability approximately by accounting where the emails are landing and infer whether the ISP has accepted it. But these do not represent the actual email deliverability rate.

1. Email servers do not return spam counts

The number of your emails that end up in your recipient's spam folder is one of the crucial aspects that you might skip while measuring. It's because the messages sent to your email servers don't return this information. You may receive a message like, the mailbox is full, or the email address you try to reach is inactive, but you will not be able to identify the right reasons why your message is not delivered.

Related guide: 9 Reasons Why Your Emails Land in Spam and What You Can Do About It

2. No accurate email landing information

You will also not be able to identify whether the email you send is landing in the spam folder, inbox, promotional, or other folders. The reason is that the filtration of emails to the recipient's mailbox varies based on different factors, including how they interact with the previous communication. The system may send the email to the inbox immediately. Still, the email gets to the spam folders in case of higher bounces, hitting more spam traps, and getting more spam complaints, so it's tricky to measure email deliverability.


What are the standard methods of testing deliverability?

We have seen that measuring or testing email deliverability is critical. But, there are some ways to measure it. Some of these email deliverability tests are as follows:

1. Seed list testing

A seed list testing is essential before running any of the email deliverability tests. A seed list will have validated and whitelisted email ids where you will send the emails before sending them to your recipients to check whether your emails are landing in the inbox. Also, it enables you to test your email across different devices and email clients.

2. Content filtering testing

Filtering your email messages based on specific content filters like Spamassassin, MessageLabs, Cloudmark is called content filter testing. Email screening for malware, spam, and other malicious or undesirable content is done by scanning the email's subject line and then forwarded via the content filtering system. Whenever an email doesn't pass the content filter test, it goes to the recipient's junk folder. The chances are that the message will be sent back to the sender with a message "undeliverable" in some cases.

3. Domain and IP blacklist testing

This testing helps check whether your domain and IP address is on the anti-spam database. The testing also includes checking domain and IP addresses and different blacklist providers to ensure your email deliverability is not affected. Use tools like MXToolBox and to check if your domain is blacklisted.

Related guides:

How Does Your IP Address Affect Your Email Deliverability

How to Check if Your IP Is Blacklisted and What to Do if It Is

4. Authentication testing

This test verifies whether your email is passing through DKIM, DMARC, and SPF checks. Both DKIM and SPF technologies are email authentication technologies used to manage inbound spam. This also checks if your IP address and the domain are on an anti-spam database. That involves checking IP addresses and domains across various blacklist providers to ensure your email lands in the recipient's inbox.

How to detect a change in your deliverability using engagement signals?

While measuring the exact deliverability might be tricky, there are some signs that you can watch to understand the trend of your deliverability rate and take contingent actions if it dips. Some of these signals you should check are as follows:

• When there are low email open and engagement rates

Low open rates in email deliverability terms signal ISPs that say that your recipients are not engaging with your content. The lack of engagement can even make your email domains get blacklisted.

Read how Project Pro achieved 3X open rates by improving their email deliverability.

• When the open rates drop for a specific mailbox provider

A dip analyzed in your mailbox provider's engagement metrics gives you a chance to be added to the blacklist or get blocked. Another vital sign identified for spam folder placement is lower open rates in the range of 1 to 2%. Deliverability professionals can read engagement rates and identify you are in trouble or moving in the wrong direction.

Related guide: 10 Effective Ways to Increase Your Email Open Rates

• When the bounce rate is above 3 to 5%

Soft bouncing is normal for large senders due to the small mailbox provider's deferrals. They accept only certain mails at a specific time when you cross higher than a 3% soft bounce rate that too at Outlook, Gmail, and other top providers, there is a high chance of getting blocked for the reputation issue.

• When the email complaint rates cross 0.2%

When the email complaint rate crosses 0.2%, it indicates a problem. The metrics can move to the lower side as smaller mailbox providers do not provide any feedback loop, which won't redirect any complaints back. So the complaints can be misleading. The campaign and recipient domain need to watch the complaints carefully.

What factors affect email deliverability?

Many factors determine if an email gets blocked, delivered, or even filtered into junk or spam folders. Some of them include the following:

1. IP addresses

The numerical identifier of the server (sender) is known as the Internet Protocol address. Every device connected to a computer network holds an IP address. So, the server's reputation can be analyzed based on IP address based on factors like send volume, user interaction, send frequency, and the percentages of undeliverable emails or bounces.

You can check the IP reputation on different services, the email deliverability service, sender score from Return-path, and more. Most organizations use other email service providers to send their marketing emails. Shared IP and Dedicated IP are the two different types of IP addresses.

Shared IP: More than one brand or company uses the same IP address to send emails.

Dedicated IP: The brand or company has its unique IP address, not shared with other companies or brands.

Read in detail: Dedicated IP Address vs Shared IP Address - Which One Should You Use?

2. Running many types of campaigns from a single domain

It's always good to use a separate domain for sending transactional emails like shipment notifications, product updates, or confirmation emails. The reason is that if your domain becomes compromised or your marketing emails are flagged as spam, your transaction emails will remain unaffected as they are sent from a different domain.

Use tools like MXToolBox or any other blacklist checkers to ensure your transactional email domain is not flagged as spam, as that would lead to blacklisting.

3. The behavior of recipients

Deliverability algorithms check the recipient's actions. For example, if an individual is not opening your email and deleting them without opening it. The ISP will send the email to the junk or spam folder. Unsubscribers and excessive complaints can lead to issues in the future.

The best option is to use different strategies that use clicks and opens. For example, you can use relevant and engaging subject lines, delete the subscribers who are not active on your wishlist, adjust the frequency as required by the subscribers, and make sure the FROM address and subject lines are not misleading in your email.

4. Content and subject line

Email body content and subject mails can trip spam filters, and thus you will have negative impacts. Make sure you have a mix of both text and images. The ideal ratio is to have 60% text and 40% image. Ensure you are not using random punctuations or capitalization. It's best to perform a spam check even if you have a small doubt, include the sender's physical mailing address and unsubscribe link, and use formatted and clean HTML code.

Email deliverability best practices to follow

The higher the email deliverability, the higher the chances of the conversion rate and the higher the chances of ROI. That is why it's crucial to improve your email deliverability metrics. Here are a few ways to improve email deliverability.

Wrap up

Getting your email delivered to a user's inbox is imperative as without it all your efforts will go in vain. Check out our guide on how to increase email deliverability for more ways to improve your deliverability that you can do right away before it's too late.

If you want to create and send actionable emails that power unique email experiences, check out Mailmodo. With Mailmodo, you'll get higher conversions and an app-like email experience for your users.

What you should do next

Hey there, thanks for reading till the end. Here are 3 ways we can help you grow your business:

  1. Talk to an email expert. Need someone to take your email marketing to the next level? Mailmodo’s experts are here for you. Schedule a 30-minute email consultation. Don’t worry, it’s on the house. Book a meet here.

  2. Send emails that bring higher conversions. Mailmodo is an ESP that helps you to create and send app-like interactive emails with forms, carts, calendars, games, and other widgets for higher conversions. Sign up now and send 10k free emails/month. Sign up here.

  3. Get smarter with our email resources. Explore all our knowledge base here and learn about email marketing, marketing strategies, best practices, growth hacks, case studies, templates, and more. Access guides here.

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