Identifying the Culprits: 8 Causes of Low Email Deliverability

By Bulk Mail Verifier | 10/3/2023, 9:00:35 AM

Email marketing is the cornerstone of e-commerce, and as many digital marketers know, email marketing campaigns are one of the most profitable and reliable ways to reach your target audience. We could discuss the many details and nuances of email marketing, but today, we’ll discuss the number one email marketing challenge: getting into your recipient’s inbox.

Simply seeing that an email has been sent is not enough; there is no guarantee that it has reached the recipient’s inbox, or your message may be filtered to the Promotions tab or, worse, to the spam folder.

Below, we’ll discuss why you might be experiencing email deliverability and inbox placement challenges. Common reasons why your email deliverability may be affected are listed below. 


Content is a vital part of email deliverability. Adding the right content to your email can go a long way to ensuring it arrives in your inbox smoothly. Here are some content components you should pay attention to:

subject line

Subject lines are essential for good email delivery. Properly formatted subject lines must be used to avoid spam folders. Be honest and transparent with the body content in your subject line, clearly defining your brand in the preceding fields, and avoid anything that seems vague, like “free,” “win,” or the bad “dear.” Remember the golden rule: never use all capital letters.

Mobile-friendly Design

If I’ve said it once, I’ve said it a thousand times: Make your email content mobile-friendly. How often have you opened an email on your phone because the subject line piqued your interest, only to find the content challenging to read? Is the format confusing? Approximately 1.8 billion people worldwide check email regularly on mobile devices. This is a precaution so you don’t lose subscribers and gain a bad reputation rather than directly improving your email deliverability.

The important thing to note here is that you can decrease the risk of your email deliverability deteriorating by ensuring you have compatible emails with your platform.


If your email contains a CTA (call to action) as a link, following proper link etiquette is essential, such as avoiding URL shortening and only linking to sites with a good IP reputation.


Your overall sender score also plays an essential role in your email deliverability. That’s why following best practices during your email marketing campaigns will help improve your email deliverability by improving your sender score. The more confident you are, the better your inbox will be and the better it will perform on other vital metrics.

Unsubscribing is Easy

This is standard industry best practice but is still very important. Always make sure your opt-out options are visible and easy to use. This helps improve email deliverability by preventing all the potential drawbacks of the complex unsubscribe process.

We know no one wants users to opt out of email marketing campaigns, but making the process more difficult will only hurt in the long run. Giving your contacts agency their support is crucial.

Contact List Quality

The overall quality of your email address list also affects email deliverability. Therefore, it is important to only send emails to email lists that have gone through our verification process to ensure you are sending emails to high-quality contacts.

This is beneficial in many ways - firstly, it prevents hard bounces in email campaigns, protecting the accuracy of your metrics and your sender score while maximizing your return on investment (ROI) ).

As you probably already know, the industry standard for global bounce rate is around 2%. This may seem like a little, but anything above this percentage is already hurting your email deliverability, not to mention that your email list will naturally degrade at a similar rate each month. Ensuring you continuously send emails to a newly verified list is one of the easiest ways to protect your sender’s reputation. As mentioned before, this will positively contribute to the deliverability of your emails.

Consistency of Email Delivery and Customer Engagement

At first glance, it might not make sense to think that following consistent, identifiable patterns in your email marketing campaigns will improve email deliverability. However, it’s more important than most people realize, as even small changes in your email marketing model can trigger spam filters and negatively impact your email deliverability.

Of course, it’s impossible to do this without changing the process, and you should never have a completely fixed schedule or pattern for email marketing. However, making small changes over time and taking calculated steps is important to ensure customers are not impacted.

Of course, this process isn’t possible without making changes, and you should never have a completely fixed email marketing plan or model. However, it’s important to make small changes over time and take calculated steps to ensure you don’t have too big an impact on customer engagement.

The truth is that the customers who interact with your emails the most do so for several reasons. Still, the time of day or week they receive your emails is one of them: Whatever you want to do with your email marketing software, What changes your email, put it in your imagination.

Email and Authentication Infrastructure

Researching your email service provider (ESP) ’s impact on email deliverability is important. First, consider the authentication protocol the ESP provides in its infrastructure. Verifying your email using the DKIM and SPF protocols is important. You may also consider obtaining a DMARC record to maximize delivery capabilities.

Most paid services automatically verify their clients’ DKIM and SPF protocols; DMARC can be an advantage. Most major ESP providers have documentation on how to comply with DMARC when using their products, and we recommend browsing your ESP provider’s support section for this information.

Suppose you are just starting your e-commerce journey and are trying to decide whether to pay for an email-sending service or use a free one. In that case, consider these authentication protocols in your decision-making process.

Email Size

The more emails you send, the more likely your messages won’t reach your recipients’ inboxes. This sounds scarier than it is, but there are some ways to deal with it:

Segment your list – Properly segmenting your list will not only reduce the number of emails you send, but it also has the added benefit of targeting the most relevant audiences for your email marketing campaigns.

Master Best Practices: This is an effortless yet effective way to ensure excellent email deliverability when dealing with large volumes of emails. Don’t worry; we’ll continue discussing good tips and best practices in this blog post.

Double Subscription and A Single Subscription

Another relatively simple and painless way to ensure better email deliverability is to avoid using one-time subscriptions as an opt-in method in email marketing. Although users only need one step to access your content, the extra work of double opt-in is negligible for individual customers, especially considering how standard double opt-in is in today’s industry compared to how you do it directly, and it affects email deliverability.

An additional argument must be made that double opt-in to verify accounts is a more secure way to ensure legitimate users sign up to view your content first.

Monitor and Blacklist your IP

We realize this advice is a no-brainer; after all, how can you get into your customers’ inboxes if you’re blacklisted? However, this is often overlooked.

However, using a blacklist monitoring tool is a great way to monitor the status and reputation of your IP, allowing you to take action to remove it from your blacklist quickly.

Leverage Deliverability Insights Tools

Like blacklist monitoring tools, delivery tools can provide valuable insights into your inbox’s location. Different tools have different features and analysis methods, but a good email deliverability analysis tool should provide you with

  • Authentication and protocol analysis.
  • Syntax and content analysis.
  • Inbox Location Report

Using these solutions before sending an email to a high-quality list is just as good as setting yourself up for a successful email marketing campaign regarding email deliverability.

Final Thoughts:

Improving your email deliverability takes time and patience. You must continually improve this strategy to send valuable emails to your audience. Ultimately, a clean, active contact list builds a good sender reputation, which is key to successful delivery. Monitor your subscriber data and email reports to ensure you send the right messages to users. If you watch these causes for low email deliverability and best practices, you can increase the chances for email deliverability.