How to Improve Email Deliverability: 5 Best Practices | WhoisXML API

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How to Improve Email Deliverability: 5 Best Practices

How to Improve Email Deliverability: 5 Best Practices

Did you know that for every dollar you spend on email marketing, you can get as much as a US$42 return on investment (RoI)? But you can’t realize that benefit if your emails don’t get delivered to their intended recipients. That’s why companies keep tabs on their email deliverability. But what is the definition of email deliverability, exactly?

What Is the Definition of Email Deliverability?

Email deliverability refers to the result of sending the right emails to your target recipients. That said, it tells you if you’re sending what specific contacts want to see when they wish to. If you don’t, chances are none of the recipients will open the messages and click embedded links. Worse, some or even most of them may mark your emails as spam. If they resort to the latter, the act will surely dampen your email sending reputation. The higher your email sending reputation is, therefore, the better your email deliverability (and RoI) gets. Simply put, your ability to evade spam filters determines your email deliverability.

Email Delivery and Email Deliverability, What’s the Difference?

Email delivery is the process of electronically sending a message to an intended recipient. It refers to whether or not your recipient can accept your message and if the receiving email address exists.

Email deliverability, meanwhile, refers to the process of improving the chances that your messages reach your target audiences and that your message lands in users' inboxes, not their spam folders. In essence, therefore, you constantly enhance your email delivery to improve your email deliverability.

Your email deliverability is the number of messages that successfully got to intended recipients’ inboxes compared to the total number of emails you sent out.

What Factors Affect Email Deliverability?

Click, open, and bounce rates are three of the statistics that companies track to determine their email deliverability. Knowing how many links embedded in emails were clicked, messages were opened, and emails were undelivered combined tell you how good your email deliverability is. But there are at least four factors that could make or break your email deliverability. Let’s discuss each factor in greater detail below.

1. Sender Reputation

Your email sender reputation is a score that your Internet service provider (ISP) gave. The higher it is, the more likely your ISP will deliver your messages to their intended recipients. If your score falls below a baseline, your ISP may automatically send your emails to the targets’ spam folder or even reject them from the get-go. Senders that send out too many emails in bulk often get tagged as spammers, and they have low sender reputation scores.

2. Email Content

In some cases, emails end up in intended recipients’ spam or junk folders because they contain spam trigger words. Examples of these include “believe me,” “do it today,” and “lifetime deal.” That happens more when the target audiences use strict spam-filtering rules or very efficient anti-spam software.

3. Email Marketing Service

Many of the most effective email marketing services today offer features like email throttling, which automatically limits the number of messages you send every day. That way you won’t get tagged as a spammer and your sender reputation and email deliverability scores remain high.

4. Email Contact Source

A lot of email marketing experts advise against buying email lists, and that’s understandable. If your email service provider (ESP) is strict, it won’t let you send messages to recipients who did not opt in to become part of your list. If that happens, your bounce rate will rise, which translates to poor email deliverability. Recipients may also mark your emails as spam because they aren’t interested in what you have to offer. It doesn’t help that email lists aren’t regularly updated so they may contain a lot of inactive addresses.
Some emails fail to get delivered due to one or a combination of the factors mentioned above. The email addresses may no longer be in use or are incorrect. You have a very low sender reputation score and are considered a spammer. Or it could be all of the above. If that’s the case, your email deliverability suffers, causing your email marketing campaigns to fail.

email deliverability

5 Email Deliverability Best Practices

There are several ways to improve your email deliverability. We listed five must dos that are bound to increase your email marketing RoI.

1. Opt for a Dedicated IP Address

Your sender reputation score has all to do with your IP address. That is, after all, what ISPs use to identify email senders. If your IP address has been tagged a spammer, therefore, your sender reputation score becomes too low, pushing your ISP to reject the messages you wish to send. The sad truth is, you can’t control that if you use a shared IP address (one that hosts more than your domain). If one of the domains that share your IP address turns out to be a spammer, your domain may get the same treatment.

2. Optimize Email Content

Apart from avoiding spam trigger words, customizing tracking links and adding unsubscribe links also help ensure your emails get delivered.

Tracking links can help you measure engagement. Doing that manually could be hard, though. Fortunately, most email marketing services today now offer that feature. Tracking links should match your email domain so they won’t trigger built-in email-filtering features that would cause your messages to end up in recipients’ spam folders.

Adding unsubscribe links to promotional emails are a must. Recipients should always have the choice to opt out, otherwise they might report you as a spammer.

3. Use Double Opt-In

Recipients who aren’t interested in anything you have to say or offer aren’t going to open your emails. Some of them may even send your messages directly to their spam folders, and that is sure to hurt your email deliverability. That’s why experts say buying email lists is a bad idea. The people on such lists never opted in to your marketing emails. Avoiding that is possible, though, if you ensure everyone on your email list did hit that subscription button. Better yet, they confirmed their choice via email, too, via double opt-in. That means after signing up for your newsletter or mailers, they reiterated their subscription by clicking the confirmation link they received via email. 

4. Employ Email Verification

Keeping your email list clean is a surefire way to maintain a healthy email deliverability score. And while doing that manually is possible, it sure is time-consuming and prone to error. There is, however, a more efficient way to do that—using an effective email verification tool.

Email verification tools check email addresses for issues, including misspellings and the absence of corresponding inboxes and mail servers. That reduces the chances that messages won’t reach intended recipients. You can also get rid of inactive and disposable email addresses from your distribution list with the tool’s help.

Email verification is a great way to keep your sender reputation score in check, improving your email deliverability.

5. Test Emails before Sending

Your domain, however, isn’t the only thing you need to be mindful of when it comes to email deliverability. You should also pay attention to your content. And there are tools that you can use to identify potential content issues that may affect your email deliverability.

You can check Spamhaus or Spamcop regularly, for instance, to ensure your domain isn’t blacklisted. Email verification software can also help spot issues in your mail server and other configuration issues if you run your company email addresses on them. And many email marketing services now have built-in content testing features before sending messages out. All these combined make for a healthier email deliverability.


To get the most out of your email marketing campaigns, you need to ensure email deliverability. Consider the factors that affect email deliverability above and keep in mind the best practices, and you’ll surely enjoy the benefits of email marketing.

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