8 Reasons Why Your Email Deliverability Is Low

Avatar for Miguel Nogueira Miguel Nogueira
Avatar for Miguel Nogueira Miguel Nogueira

October 26, 2022

6 min read

8 Reasons Why Your Email Deliverability Is Low

Email marketing is a cornerstone of e-commerce, and as many digital marketers know email campaigns are some of the most profitable and reliable ways of reaching your target audience. There are many details and nuances to email marketing we could discuss, but today we’re going to talk about the very first email marketing challenge: reaching your recipient’s inbox.

Simply seeing an email as delivered is insufficient, there is no guarantee that you’ve landed on the recipient’s inbox, your message could have been filtered to a promotional tab or, even worse, the spam folder.

Below we’ll discuss some of the reasons why you could be facing challenges in your email deliverability and inbox placement.

Common reasons why your email deliverability is being affected

1. Content

Content is a very important part of your email deliverability. Having the right content in your email goes a long way toward ensuring your inbox landing is good. Here are some of the components of content you should pay attention to:

Subject lines

Subject lines are important for good email deliverability. A properly formatted subject line is mandatory to avoid the spam folder. Be truthful and transparent about your body content in your subject line, identify your brand clearly in the front field, and avoid anything that sounds sketchy, such as “Free”, “Win” or the ever-so-terrible “Dear”. And remember the golden rule, never, ever, use all caps.

Mobile friendly design

If I said it once, I said it a thousand times: make your email content mobile-friendly, how many times have you opened an email on your phone because the subject line interested you only to find an unreadable, unformatted mess? Around the globe, close to 1.8 billion people regularly check emails on their mobile devices. This is more of a preemptive measure to not lose subscribers and gain a worse reputation, rather than a direct improvement in email deliverability.

The important thing to note here is that by making sure you have a platform-compatible email you’re minimizing the risk of worsening your email deliverability.


If your email is going to have CTA (Call to action) in the form of links it is important to adhere to proper link etiquette, such as avoiding shortening your URLs and only linking to websites with good IP reputation.

2. Reputation

Your overall sender score also plays a big role in your email deliverability. This is why following best practices during your email marketing campaign will help to improve your email deliverability through your rising sender score. The more trusted you are, the better your inbox placement will be and the better other crucial metrics perform.

Easy unsubscribe process

This is a very standard best practice in the industry, but very important nonetheless. Always make sure that your unsubscribe options are visible and easy to use. This helps your email deliverability by preventing all eventual downsides of having a difficult unsubscription process.

We understand no one wants users to unsubscribe from their email marketing campaigns, but making the process harder will only be harmful in the long run. Giving your contacts agency over their subscription is paramount.

Contact list quality

The overall quality of the email address lists can also influence your email deliverability. This is why it is important to only send emails to email lists that have undergone a verification process in order to assure that you’re emailing high-quality contacts.

This is beneficial in several ways - first and foremost, it prevents hard bounces from occurring in your email marketing campaign, which not only protects the accuracy of your metrics but also protects your sender score alongside guaranteeing you're maximizing your return on investment (ROI).

As you may already know, the industry standard for a bounce rate is around 2% globally. This may not seem like a lot, but a single percentual value above that is already causing harm to your email deliverability, not to mention that email lists naturally decay at a similar rate per month. Always being certain you’re emailing a freshly verified email list is one of the easiest ways to protect your sender reputation, which as explained before will contribute positively to your email deliverability.

3. Emailing consistency and customer engagement

At first, glance, saying that following consistent recognizable patterns in your email marketing campaigns will improve your email deliverability may not make much sense. However, it is far more important than most people are aware of, even small changes to your email marketing patterns can trigger spam filters and negatively impact your email deliverability.

Naturally, the process is impossible without change, and you shouldn’t have an absolutely static email marketing schedule or pattern. It is important, however, to make small changes over time and take calculated steps to make sure you don’t impact your customer engagement too much.

The truth is, customers who often interact with your emails are doing it for various reasons, but the time of day and or week they receive your emails is certainly one of them - whatever changes you’re looking to make to your email marketing schedule, keep this in mind.

4. Email authentication and Infrastructure

It is important to do some research on the impact your Email Service Provider (ESP) can have on your email deliverability. The first thing you’re going to want to pay attention to is what authentication protocols your ESP offers in its infrastructure. Properly authenticating your emails with DKIM and SPF protocols is very important. You may also want to consider having DMARC records to maximize your deliverability.

Truth be told, most paid for services will have DKIM and SPF protocols automatically authenticated for their customers, DMARC may come as an additional feature. Most major ESPs have documentation on how to be DMARC compliant using their product and we encourage you to explore your ESP’s support section for this information.

If you’re just starting out your ecommerce journey, and are on the fence about paying for an email sending service or using a free one these authentication protocols should be weighed into your decision making process.

5. Email volume

The more emails you send out the more opportunities there are that your message will not land on the recipient’s inbox. This sounds more intimidating than it actually is, but there are ways for you to fight this:

  • Segment your lists: Segmenting your lists properly will not only reduce the amount of emails you’re sending out but it has the added benefit of targeting the most relevant audience for your email marketing campaign.
  • Keep up with best practices: This is a very simple and yet effective way of guaranteeing great email deliverability when dealing with large numbers. Don’t worry, we’ll continue to discuss some good tips and best practices during this blog post.

6. Double opt-in versus single-opt in

Another relatively easy and effortless way to guarantee better email deliverability is to avoid using single opt-ins as a subscription method to your email marketing. Although it is less of a step for the user to get to your content the added work of a double opt-in is negligible for the individual customer, especially given how industry standard double opt-ins are nowadays, when compared to how it can directly affect your email deliverability.

There is also the added argument that using a double opt-in as an account verification method is a much more secure way to ensure that you have legitimate users signing up for your content in the first place.

7. Monitor your IP for blacklist placement

We understand that this suggestion is really a no-brainer, after all, how can you reach your customer’s inbox if you are blacklisted from getting there? This is, however, often overlooked.

Using a blacklist monitoring tool is a great way to keep an eye on your IP’s health and reputation, allowing you to take quick action to be delisted from these blacklists.

8. Take advantage of deliverability insight tools

Much like the blacklist monitoring tools, a Deliverability tool can help provide you with invaluable insight regarding your inbox placement. Different tools have different features and analysis methodologies, but in general, a good email deliverability insight tool should provide you with:

  • Authentication and protocol analysis
  • Syntax and content analysis
  • Inbox placement report

Taking advantage of these solutions prior to sending out your emails to high-quality lists is about as well as one can prepare oneself for a successful email marketing campaign in terms of email deliverability.


We hope this post has provided you with useful and relevant information regarding what can affect your email deliverability and how you can improve it, or at the very least, preemptively protect it.

Here is a short summary of what we discussed today:

  • Content
  1. Relevant and transparent subject lines
  2. Mobile friendly design to protect important metrics
  3. Don’t use shortened URLs
  • Reputation
  1. Easy unsubscribe process
  2. Verify your email lists to avoid bounces
  3. Keep bounces under 2%
  • Email consistency and customer engagement
  1. Don’t make abrupt changes to your schedule or patterns
  2. Keep accurate metrics of your customer's engagement and use that to your advantage
  • Email Authentication and Infrastructure
  1. Authentication Protocols are very important
  2. Choose a trustworthy ESP
  • Email Volume
  1. Segment your lists
  2. Stick to best practices when emailing in large volumes
  • Double opt-in versus single opt-ins
  1. Both are valid, but double opt-ins are far superior
  • Use blacklist and deliverability insight tools to maximize email deliverability

That’s all this time around, happy emailing!

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