How to Improve Email Deliverability

If you aren’t getting the results you want from your campaign, there are several measures you can take to improve email deliverability and be assured that your mailings reach your intended audience. Along with having a high open rate, the right call-to-action, and a subject line that attracts attention, you’ll need to know the best email deliverability practices so that your campaign gets the results you want.

What is Email Deliverability?

Email deliverability is the rate at which your campaign mailings make their way to their desired destination (user’s inbox). According to reports, the changes are high that 1 out of 5 emails you send will not reach your intended recipient’s inbox. These emails either find their way into spam folders or are deleted by the internet service provider (ISP). Email deliverability issues often result from shady email practices and not sticking to the rules laid out by ISPs.

Email deliverability is not the same and email delivery. Email deliverability is a process that marketers go through to ensure that their campaigns are delivered to their customers’ inboxes and not to their spam or junk folders. Email delivery is when your campaign mailings are accepted by the mail server of your intended recipient.

Why Does Email Deliverability Matter?

Email has become a major communication method with hundreds of billions of messages being sent every day. And while most of these emails contain messages that the recipient has requested, about half of those sent are spam. Because of this influx of spam, mail providers and ISPs now filter out the spam messages that come into their systems and prevent those and similar messages from reaching their users inboxes.

This is good news for recipients because it keeps them from seeing messages they didn’t want or ask for. Plus, mail service providers know which messages have not been opened and which have been reported as spam by their users. The provider keeps a history of this activity and if your mailings have a low open rate or a high spam reporting rate, your mailings will be labeled as spam. However, this spam detection makes a marketers job more challenging because the marketer must always be aware of how their campaign mailings are seen by spam detectors, causing them to always be on the search for new ways to improve email deliverability.

The good news for your marketing campaign is that there are ways to improve email deliverability. Most marketers use an email verification service that performs a variety of checks that tell a marketer whether a message will reach it’s intended recipient’s inbox and that the marketer’s email address doesn’t appear on any spam or block lists. By improving email deliverability, you’ll get good inbox placement, and your mailings will be delivered to your customers’ inboxes and not to their spam or junk folder. And it starts by testing email deliverability before you send your campaign to your customers and mailing list subscribers.

How Do Email Providers Determine Deliverability?

Email providers take many things into consideration before they determine if a message is spam and if it comes from an address that sends spammy messages regularly. Here are the things to watch out for to keep your email address off of spam and block lists.

It’s important that you consistently monitor that status of your campaign’s email address and how your subscribers interact with your mailings. When you have a high sender score and open rate, a low bounce rate, and you deliver a message your subscribers want to hear, you’ll improve email deliverability and ensure the success of your campaigns.

Improve Your Deliverability with These Best Practices

There are proven techniques that can help you improve open rate and prevent delivery failure. These are the email deliverability best practices performed by some of the biggest marketing brands.

1. Use Double Opt-in to Collect Quality Addresses

When using a pre-checked box to gather subscribers, you are most likely going to collect addresses that will hurt your deliverability rate due to spam complaints. A double opt-in, however, is a process where users who desire to subscribe to your mailing list receive a message confirming their desire to join your mailing list.

This method can decrease the number of subscribers that you can get. However, it also increases the quality of subscribers that you get. This way, you only get subscribers who are genuinely interested in what you have to offer and would be less likely to unsubscribe from your mail list. This will improve deliverability, increase engagement, lower your bounce rate, and fetch you higher quality leads.

2. Make Sure the Addresses on Your List Are Valid

Even if you use double opt-in, people change email addresses. From time to time, you should check email address validity. These checks will tell you if the receiving email server will accept your message and deliver it to your intended recipient’s account. To keep your mailing list clean, remove any addresses that have a low probability of being deliverable.

And if you collect addresses from other sources, those sources may contain spam traps and may not be current. Performing email validation will also help you identify spam traps and other irrelevant addresses from your mailing list. When you find these addresses, remove them for your mailing lists.

Sending messages to addresses that don’t exist or are spam traps will have a negative effect on your sender reputation. Use an email validation service like ZeroBounce to identify addresses that will leave your campaign vulnerable and to decrease your bounce rate.

ZeroBounce email verifier to improve email deliverability

3. Prevent Mailings From Being Marked as Spam with a Simple Opt-Out Process

Under the CAN-SPAM Act, marketers must provide a way for subscribers to remove themselves from any mailing list. It also requires marketers to offer a simple opt-out process for their subscribers. To comply with this law, put the opt-out button where it can be found quickly and easily. Also, provide clear instructions for how to unsubscribe. Consider using a one-click unsubscribe and a successful unsubscribe message to make the process easier.

If your opt-out button is hidden or if you don’t provide one, your email authority can be affected as users who are unable to unsubscribe begin to mark your messages as spam. So, in addition to complying with the law, providing an opt-out button on your website or in your messages can improve deliverability of email because your email address is less likely to be reported as spam.

4. Keep Your Active Subscribers and Delete the Inactive Ones

Improving deliverability is all about following ISPs rules to gain their trust. Inactive subscribers affect your deliverability because mail sent to these addresses are seen by the mail server as bounced messages. To prevent your deliverability rate from dropping, clean up your mailing list regularly.

During your routine check of the mailing list, perform a verification check, and remove any addresses that are flagged as inactive or spam traps. Also, remove subscribers who get your messages but do not engage. When subscribers don’t interact with your mailings, your open rate goes down.

5. Use a Dedicated IP for Large Mailing Lists

Once your daily emails sent reach 25,000, it's time to get a dedicated IP. ISPs can block an entire IP pool if they suspect you just keep adding IPs to your list. Once you get a dedicated IP, ensure to warm up your email account. In the beginning, send mailings in small batches and only every few days.

While you’re warming your list, track your open rate and keep your bounce rate low to increase email deliverability. As your subscribers begin to engage more with your messages, you can add more addresses to each batch you mail and increase the frequency of your mailings. Just be cautious as you increase your mailings. Take it slow and keep track of how well your campaign is performing. The goal is to build trust with email providers so that your messages are delivered to your subscribers’ inboxes and not flagged as spam.

6. Maintain a Consistent Brand Image and Contact Information

Name recognition is important in email marketing, as your business name is your brand and it’s how people recognize your business and products. You should also be consistent with your address and other information you include on your company mail.

Ensuring a consistent brand name, image, and contact information is another technique for how to improve email deliverability. It also ensures your subscribers don’t confuse your mail for that of other businesses. When your subscribers recognize your brand, they are more likely to open and respond to your mailings. If you flip-flop between the name you choose to represent your brand with, your subscribers may mark your messages as spam.

7. Target Your Message to Your Subscribers’ Needs to Increase Engagement

You can also improve deliverability with email segmentation. Popular segmentation is based on demographic, location, past purchases, and position in the sales funnel. A research carried out by Mailchimp showed that segmentation of emails resulted in a higher open rate, more clicks, and less bounce rate.

It is important to note that ISPs favor your messages and increase your authority when you have a high engagement. Since people have shown that they engage with mailings that are specifically tailored to their needs, mail segmentation is the best way to increase engagement.

8. Choose the Number of Mailings You Sent to Your Subscribers Carefully

The number of mailings you send to your subscribers each month can lead to a decreased delivery rate. While the issue of surplus emails can be subjective, the most successful marketers are stated to send between two times a week and eight times a month.

The constant barrage of emails can cause even your most engaging subscribers to stop reading your messages, or worse yet, unsubscribe or mark as spam. It also helps improve email deliverability if messages aren’t erratic or spontaneous. Ensure emails are sent in a consistent hour and day every time and avoid long breaks.

9. Write a Clear and Meaningful Subject Line That Will Get Your Emails Opened

There are certain keywords that can get your mailings classified as spam. A couple of them include Free, Risk-Free, Call Now, and more. There are hundreds of keywords that you should avoid. However, a rule of thumb in order to avoid spammy subject lines is to focus on the value of your message and not try to push, over-sell, or create an unnecessary urgency.


Your mail delivery rate is the most important aspect of your email campaign. To ensure your mailings are getting to their desired destinations, follow the 9 best email deliverability practices outlined in this article.

How to Improve Email Deliverability – FAQs

What affects email deliverability?

The delivery rate can be affected by a couple of reasons. The most obvious is by failing to follow the best email deliverability practices. Not sticking to ISP rules, sending emails to the wrong users, and too many emails being sent at successive intervals are among them.

What tactics can be followed for improving email marketing deliverability?

The more engagement your emails get, the higher your mailing authority is. To improve email marketing deliverability, simply follow ISP guidelines, get genuine mail subscribers, and filter your mailing list for spam traps.

What is a good email deliverability rate?

95% and higher is considered a good delivery rate according to ISPs and email marketers worldwide.

How do you ensure email deliverability?

The fundamental aspect for ensuring email deliverability is having the right mailing list. Other guidelines include following ISP’s guidelines and employing email segmentation for more engagement.

Why would email not be delivered?

If your emails are considered spam by ISPs, your messages are automatically deleted or sent to the spam folder.