The vast concern of enterprises for email deliverability tells us that email is still king. The success of any enterprise on the internet depends on email.

Users today rely on email to receive all important and valuable documents, subscriptions, and notifications. Businesses know the power of email and utilize it list to start marketing campaigns, send surveys, or notify their customers of new products and services. A successful email campaign converts to real revenue. A consumer who clicks and purchases a product via an email link shows that the brains behind a marketing campaign have done their job. However, a business can be hounded with problems in email deliverability and they can miss out on sending thousands of emails. The problems can be traced to technical issues or a certain laxity incorporate processes as we shall see.

What is email deliverability?

Email deliverability is the ability to deliver emails to subscribers’ inboxes. It is what some marketers use to gauge the likelihood of their email campaigns reaching their subscribers’ inboxes related to actual delivery–like ISPs, throttling, bounces, spam issues, and bulking. Elements that hurt deliverability include sending without custom authentication, using single opt-in, sending from a free domain email address, using spam flashing email subject lines, making it difficult to unsubscribe, using URL shorteners, and sending emails with too many images.

Email deliverability means your intended recipient gets your email message. It sounds simple, right? But if you are a corporation with millions on your subscribers’ list or if you are even a midsized one with thousands, engagement can be a complex task. Email deliverability failure can be a crisis for a company. We are in an era where we are transitioning to paperless electronic mediums. Thus, important emails such as utility bills and credit card statements are now being delivered via email. In addition to this, strictly online services such as membership confirmations, password resets, and shipping notifications are being relayed via email.

Imagine not being able to send these important emails on time. The result will be a domino effect that will interrupt business processes and cause customer dissatisfaction. A company can lose thousands of dollars from failed email deliverability. According to ReturnPath, 21% of opt-in emails never really make it to the inbox. This means that there are a significant number of subscribers who have never heard from you.

The biggest businesses have millions of subscribers, thus, 21% translates into large numbers. These customers failed to get their email for several reasons. It may have been routed to the junk folder or the business sending it has been blocked by the Internet Service Provider or ISP as it’s known. Despite the reasons, the end is still the same; potential loss.

When to check email deliverability?

If you’ve sent out an email it is important to check immediately if it has reached the recipient. It’s easy to ensure deliverability with small amounts of sends, but things can get more difficult as you send out thousands or millions of emails. If you are a large business with an email list containing a high volume of subscribers, there are many tools out there that can keep the guess-work down and allow you more insight to your deliverability metrics. You can use these tools and techniques for checking email deliverability and possible reasons for failure. There are many reasons behind an email failing to reach your target. As we’ve mentioned, your ISP may have mistaken your message as SPAM and isolated you in its spam filtering process. Perhaps the ISP may have also been having problems with the large bulk of emails coming from you at once. If you are a company using multiple DNS records, it is good practice to regularly review and monitor your DNS. You should also monitor your IP address and domain reputation.   These quick look-ups can assist in troubleshooting your mailing reputation and give you some valuable information on how to remediate your issues. It’s also important to track delivery times with your Mail Handler. Simple tools and practices, such as these, will facilitate a better email delivery footprint and ensure that the email is delivered to its intended recipient.

How to improve email deliverability

There are numerous ways to improve email deliverability. The two most important methods are having verified email addresses and maintaining a good sender reputation.

email deliverability

Verified and Validated the list of subscribers

This is what everything starts with. It’s great to have a large email marketing list, but it’s not enough.  If you want to monetize the subscribers you have, you must ensure that their emails are correct and deliverable. Verifying your emails prior to deploying mail to them improve your campaign’s chances of successful delivery and your sender reputation. Keeping your lists clean and verified will ensure a low hard bounce rate, minimize your complaints, and protect your mailing resources (IPs and Domains) from being blocked or blacklisted. Learn more about why you should verify and validate your lists in a separate article we have prepared OR given our service a try and Get your first 200 validations now!

Good Sender reputation

This is what helps you land in the inbox while the opposite route you on the junk folder or worse, block you from delivering. As mentioned, having valid and clean email addresses will help increase your sender reputation but it does not stop there. You must maintain a low hard bounces rate, protect your resources, and keep complaints at a minimum in order to boost your sender score reputation. But what’s often undervalued is the content and frequency in which you send. Make sure you deploy marketing campaigns that are relevant to your audience and the content they wish to view. A car dealership sending a coupon for an oil change has far better engagement propensity than sending an ad for big-screen TVs. Know your audience. Once you’ve established credible content, it’s important to find a cadence of frequency to send your emails. You should never be bombarding your subscribers with multiple emails per day unless the message is needed for such frequency. Working through a proper tempo on your marketing emails will decrease the chances of your emails bottlenecking at the gate and increase the chance for the ISP to allow them to inbox.


Make sure your template or HTML is properly coded and formatted. Your email needs to be responsive, to make sure your users have a high-quality experience. Avoid using multiple hyperlinks and URLs for fear of being auto-moved to the spam/junk folder.


Send emails at regular intervals to avoid suspicion. High volumes of email get the red flag. SPs notice trends with regards to bulk mail, so it’s important to find a constant flow that works for both your engagement and your delivery footprint.

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Email deliverability best practices

Be trustworthy and engaging

The deliverability of your emails depends on your interaction with your subscribers. As we’ve mentioned, ISPs react to subscriber behavior and may decide to block you. Respecting your subscribers by setting clear expectations will give you fewer hassles. The more positive engagement you have with your campaigns, the higher your chances of future deployments delivering becomes.

Be responsible with your email list

Make sure your email list is coming from certified users and active subscribers. Regularly filter out inactive addresses and set a maintenance schedule to periodically re-clean your subscribers to validate their addresses are still deliverable and safe to send to.

Choose a good Email Service Provider

Get quality software to handle all your email marketing. You should look for something sophisticated enough to handle bounce codes and connection optimization. Also, pay proper attention to ESP average delivery rates and metrics to ensure optimal delivery to all domains. Make sure your ESP has flexible and easy-to-use template builders and list segmentation for better operations.

Create great content

Ultimately, it is content that will hook your subscribers and you should be savvy enough to know what works. Great content gets read or at least gets scanned but bad content pushes your emails into irrelevance or even worse, the trash folder. Create content that you think your subscribers will make an effort to read and want to see. Follow copywriting practices that are up to date and resonate with a new generation of subscribers. Make sure your email looks proper on all the screens and devices. Always use the users’ language. Never be afraid of any kind of personalization or targeting.

Don’t write spammy sounding subject lines

Spammy emails are easily identifiable with the way they are constructed. The subject lines by themselves will tell you that it’s spam and most users will delete or ‘mark as spam’ before ever even opening it. Your content begins with your subject line so you must take the time to think carefully of words that would resonate with your subscribers and reflect your email marketing goals. ISPs won’t necessarily block you from using certain catchphrases but it’s better to avoid it for the sake of your users.

Manage complaints

If you have received a lot of complaints, you must act immediately. Complaints are a serious issue that can get you blocked on ISPs. Set up a separate email address where you can receive emails from your email marketing service or an anti-spam organization about complaints. Register this email to show that you that you’ve given thought about the email spam issue. Make your unsubscribe information easily accessible and simple to use. Some of the most common complaints occur from the inability to remove themselves from your list.

Monitor your reputation metrics

Your reputation metrics matter if your messages are going to get delivered successfully. There are actual metrics to look for to ensure that you are in good standing. You can see your reputation score from a software called Sender Score. The software can rank a sender from 0 being the worst to 100 which is the best. The ranking would depend on complaints, returned emails, external reputation and number of unknown users.

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