All Articles 10 traps that can kill your email deliverability rates

10 traps that can kill your email deliverability rates

A laptop with a person typing an email.

Email deliverability is a huge issue for businesses of all sizes. If your email doesn't reach the inbox, it's as good as not being sent at all.

When your email deliverability rates drop, it can mean a lot of wasted time and money. Not to mention the lost opportunities for sales, leads, and engagement.

The good news is, there are plenty of things you can do to make sure your email deliverability rates stay high. In this article, we'll cover 10 of the most common traps that can kill your deliverability rates. Avoid these traps, and your email campaigns will stand a better chance of reaching the inbox of every subscriber.

What is email deliverability?

Email deliverability is the process of ensuring that your email reaches the inbox of your subscribers.

It's not enough for your email to be sent successfully. You also need to make sure it arrives in the inbox and isn't filtered as spam.

If your emails are being sent to the spam folder, you have a deliverability issue.

Email deliverability is a complex issue, and many factors can influence your rates. For example, your sending reputation, the content of your email, and even the time of day you send can all impact whether or not your email reaches the inbox.

However, some common traps can kill your email deliverability rates. If you can avoid them, you'll be on your way to high deliverability rates.

1. Buying third-party email lists

One of the quickest ways to kill your email deliverability rates is to buy a third-party email list.

Email providers like Gmail, Yahoo, and Outlook use engagement data to determine whether or not to send emails to the inbox or spam folder.

When you buy a list of email addresses, you're starting from scratch with no engagement data. This tells the email providers that your messages are less likely to be relevant and engaging, which can hurt your deliverability rates.

Most importantly, when you buy an email list, you don't know if the people on that list want to receive your emails so they're more likely to unsubscribe and mark your messages as spam. These users didn't opt into your list and according to GDPR legislation, this is illegal and you could be fined.

2. Using all caps in your subject line or email copy

When you use all caps in your email subject line or copy, it looks like you're shouting at your subscribers. This can come across as aggressive and can make your email less likely to be opened.

In addition, using all caps in your email can trigger spam filters. To avoid this, stick to using sentence case or lowercase letters in your subject line and email copy.

3. Keyword stuffing and trigger words

Email providers use spam filters to protect users from unwanted and irrelevant emails.

For example, if you're an e-commerce candle business, you shouldn't stuff your email copy and subject lines with the word "candle" just to get past the spam filters. This will not only turn off your subscribers, but it will also flag your email as spam.

To avoid keyword stuffing, focus on writing quality content that is relevant to your subscribers. Use natural language and target keywords thoughtfully to avoid coming across as spammy.

Spam filters also look for certain keywords that are associated with scammers and spam. These are known as trigger words.

If your email contains these words, there is a good chance it will be filtered as spam. Some examples include:

  • FREE!
  • 100% satisfaction guarantee
  • Act now!
  • Click here
  • This is not a virus
  • Your satisfaction is guaranteed

So, avoid using these words in your email copy if you want to stay out of the spam folder.

Useful tip: Run your email copy through a spam checker tool like Litmus Spam Filter Checker or Email on Acid Spam Score Checker to see if it will trigger any spam filters.

4. Using exclamation marks

Exclamation marks are often seen as a way to add emphasis to your message like when you want to make a strong offer, or if you're announcing something exciting. But don't go overboard - too many exclamation marks will turn people off and make your email seem unprofessional or spammy.

Stick to one or two at most.

For instance, let's say you're emailing a list of potential customers about a new product you think they'll love. You don't want to write an email that says "You need this new product!!!"

Instead, try something like "I'm excited to tell you about a new product that I know you'll love. It's called XYZ and it does ABC. I think it would be perfect for you because of XYZ."

You can see how the exclamation marks in the first example make the email seem much less genuine, and almost like you're trying too hard to sell something. The second example is more low-key but still conveys excitement without coming across as desperate.

So, use exclamation marks sparingly for the most impact - a few here and there are fine, but too many will make your email seem like spam.

5. Poor spelling and grammar

It's important to proofread your email is well-written and that there are no typos or grammatical errors. They make you look unprofessional, and could hurt your deliverability rates.

After all, if you received an email from someone with poor spelling and grammar, would you be likely to trust them? Or would you think they were spam?

The same goes for your subscribers. So take the time to proofread your email before you hit send, to make sure it's error-free.

6. Adding attachments

Adding attachments to your emails can be a great way to give subscribers more information about a product or service. However, large attachments can quickly eat up your subscribers' bandwidth and storage space.

Spam filters are designed to block attachments by default. So, even if a subscriber wants to download your attachment, they might not be able to unless they adjust their email settings.

To avoid these problems, link to the file on a website instead. Or, consider using a file-sharing service like Google Drive or Dropbox to host your attachments. This way, your subscribers can download the files at their convenience and you will minimize the impact on your email deliverability rates.

7. Embedding forms

If you want to survey your customers, for example, don't attempt to embed the form in your email because most email providers will automatically block any email that contains a form. Instead, use a call-to-action button or link to a landing page where they can fill out the form.

8. Adding too many images

Images are an effective way to break up text and make your emails more engaging, but too many images can hurt your deliverability rates.

That's because some email providers will send emails with a lot of images or large file sizes straight to the spam folder, and even if they don't, too many images can make your email look like spam. So, use images sparingly and make sure they're relevant to the content of your email.

To make sure that your images aren't too large, compress them before you add them to your email. You can use a free online tool like to do this easily.

9. Including rich media

Just like with images, including video or JavaScript in your email can impact email deliverability.

Most email clients block images by default, and the same goes for rich media. So, if you're planning on using video or code, it's best to stick to plain text and images.

Link to videos instead of embedding them in your email. That way, your email is more likely to get through spam filters and your subscribers can view the content you're trying to share. When it comes to email deliverability, it's better to err on the side of caution. So, if you're not sure whether something will impact your deliverability, it's best to avoid it.

10. Sending emails to subscribers that have bounced multiple times

If a subscriber's email address has bounced multiple times, there's a good chance that it's no longer active. Sending emails to these addresses can damage your sender reputation and you could see a decline in your deliverability rates.

So, make sure that you regularly remove inactive subscribers from your list. You can do this manually or use an email validation service to automate the process. If you're using Maildroppa, we'll automatically remove any bounced email addresses from your list for you.

Bonus tip:

Use double opt-in to avoid typos and fake email addresses

One of the best ways to ensure high deliverability rates is to use double opt-in when someone subscribes to your mailing list. With double opt-in, subscribers must confirm their email address before they're added to your list.

This may seem like an extra step, but it's worth it because it ensures that you're only sending emails to people who have verified that they want to receive them. And, it helps to avoid typos and fake email addresses, which can quickly damage your sender reputation.

With Maildroppa, double opt-in is always enabled by default. So, you can rest assured that your list will be clean and your deliverability rates stand a good chance of staying high.

If you're not using Maildroppa, make sure that you enable double opt-in in your email marketing service.


Maintaining high email deliverability rates is key to the success of any email marketing campaign.

There are many things you can do to make sure your emails reach the intended recipients, but some of the most common mistakes include buying third-party email lists, using all caps in your subject line or email copy, keyword stuffing, adding attachments, embedding forms, and including rich media and too many images.

It is also important to remove inactive subscribers from your list and use double opt-in when someone subscribes to your mailing list. Avoiding these traps will help your email campaigns out of the spam filters and improve the chances that your subscribers will see your emails.