All Collections
Common reasons emails may land in the spam folder
Common reasons emails may land in the spam folder

An overview of the most common reasons why your email may go to spam and what to do about it

Petra Molnar avatar
Written by Petra Molnar
Updated over a week ago

Did your email land in the spam folder? Well, friends, welcome to the exciting world of email marketing. Sooner or later, it happens to everyone—seasoned marketers included.

First of all, don't feel bad about it.

Second, learn from it, so that you can avoid it next time.

And when it comes to learning, we've got good news and bad news for you.

  • The bad news is that mailbox providers like Gmail, Outlook and Yahoo never share what exact rules they use to filter out emails as spam. So it's hard to prepare for every possible scenario.

  • But the good news is that there are some common reasons why this may happen. And by avoiding these you can make significant improvements. 🙌🏻

Let's take a look at them.

1. Your recipients didn't opt in to get promotional emails from you

The most important rule of email marketing is to always make sure you send emails to people who opted in. You need their consent and should never assume that they want to hear from you.

You can get their consent by using language in your sign-up forms that is clear and transparent. If you’ll be adding them to your email list and sending them promotional emails, let them know.

Need some ideas? Take a look at the below example:

Sign up to my email list and grab your copy of [name of your lead magnet].

Your information is 100% secure and will never be shared with anyone. By signing up you’ll be added to my email list where I share [frequency] [topic of emails]. You can unsubscribe at any time.

Think about it this way. If you send emails that your recipients don’t expect or recognize, they may mark them as unwanted spam. When they do that, their email server will filter out all your future emails as well.

The more your recipients mark your email as unwanted spam, the more your emails will miss the inbox. This can damage your sender reputation in the long run.

2. You have low engagement rates

Spam filters also check how much your recipients love your emails. If your audience doesn't engage with your emails in a positive way, they take it as a sign that your emails aren’t wanted. And next time they may not deliver them to the inbox.

What are signals of positive engagement?

Positive engagement is when they:

  • Open your emails

  • Click on links in your emails

  • Move your email out from the spam folder

  • Add your email address to their Contacts or Address list

  • Reply to your email

  • Forward your email to someone else

After you send out an email in Flodesk, you can track how your recipients engage with it.

On your Emails dashboard, hover over the sent email's card and click on View Results.

You’ll see your email's performance, including:

  • Open rate

  • Click rate

  • Desktop or mobile viewing preference

  • Unique opens

  • Unique clicks

  • Deliverability

  • Unsubscribed

  • Bounced

  • Marked spam

Want to know how your email performed compared to others?

Looking at benchmarks can help you understand how much room for improvement you have with your emails—or if you’re leading the pack. You can learn about the latest email marketing benchmark figures with Q1 and Q2 2019 data here.

Keep in mind that average engagement rates, open rates and click rates vary by:

  • Industry

  • Company size

  • Geography

So make sure to compare your email’s engagement with others in similar industries and locations as yours. (Context is everything.)

3. You have no unsubscribe link or it's hard to find in your email

Every promotional and marketing email has to have an unsubscribe button or link. And not just because it’s the law. If you think about it, having a prominent unsubscribe link or button is also in your best interest.

Because your goal should be to have a healthy, engaged email list, this includes letting subscribers go when they want to unsubscribe.

Maybe they feel you can’t serve them anymore, or they don’t like the color you picked for your last newsletter header or maybe they thought they were signing up for something completely different.

Whatever the reason, when people want to unsubscribe, they want to do so quickly and easily.

So what happens if they can’t find the unsubscribe link? They may send you an angry email asking you to remove them from your list.

Or worse—and what happens even more often—is that they mark your email as spam. And this can hurt the success of your future email campaigns.

4. Your email design has a bad text-to-image ratio

We’ll be the first to tell you: Stunning images and design play a crucial role in email marketing (Flodesk's proprietary Layout blocks, anyone?). But don't forget about your actual email text.

Text-based content is crucial for your email, because text can be read by all email applications. If there's a network connection problem, your images may not load at all in your recipient's inbox. So if your email is made up of only images, your readers may get a blank email without any clues about what you wanted to share with them.

Also, spam filters can skim through text easily. That's why more and more scammers use image-heavy emails. They try to mask their fraudulent activities and avoid text-based spam filters. And you wouldn’t want to be mistaken for a scammer, would you?

Does this mean that you should stop adding images to your emails? Of course not.

But it means your emails shouldn't be images only.

Note: Layout blocks—even the ones that only contain text—will render as static images in the final email design.

We recommend using both text blocks and layout blocks in your emails to keep things both branded and functional. And as a best practice, always have more text than images in your email.

5. You’re using spam trigger words

Spam filters not only analyze your email subject lines but also the body of the email. Sometimes these words seem harmless. But as they have been often misused by scammers and in phishing emails, they can alarm spam filters.

Automational released a list of 470+ keywords that could raise the spam filter alarm. Review this list and try to avoid these words and phrases in your email campaigns.

There are also free tools that can test the spamminess of your emails before sending them to your whole audience. For example, Mail-Tester checks your email and gives it a score on a scale of 1-10. They tell you what’s working well and where you could improve.

Lastly, you can also send a test email to yourself from within the Flodesk email editor.

  • Click on the paper plane icon in the upper left area of the screen.

  • Add a subject line.

  • Add your email address as the recipient.

  • Click on Send test now.

If the test email lands in your own spam folder, that's a sign that you need to change your design or email copy.

6. You’re sending your marketing emails from a free email address

Emails sent from free Yahoo, iCloud,,, Hotmail and even Gmail addresses have a much higher chance of being flagged as spam than a custom domain, such as

Why? Because scammers often use these free email services. They can easily set them up and can remain anonymous.

When you buy your website's domain and domain email address, it gets officially registered for you. It establishes you as a trustworthy, legitimate business. So if you're serious about email, this is your best bet. It looks more professional, too!

As an additional important step, make sure to authenticate your sending domain email address. You can read about how to authenticate your domain via DKIM here.

Once your domain is verified, it's one more signal that you’re not impersonating anyone else when sending marketing emails from that domain. This boosts your sender reputation and positively influences deliverability of your email campaigns.


  • If every now and then one or two of your emails land in the spam folder it's nothing to be worried about. It happens to the best of us!

  • However, it’s a good idea to be aware of some of the most common reasons why emails get flagged as spam so you can stay out of the junk folder—and get into actual inboxes.

  • When someone receives an email they don’t want or can't remember signing up for, they often mark it as spam. Especially if they can’t find the unsubscribe button or link easily.

  • If many people mark your marketing emails as spam, it will not only hurt your sender reputation, but it also means that your emails won't get delivered to the inbox. They’ll land in the junk folder.

  • Your email design and text plays a big role in determining whether or not your email gets marked as spam (both by actual subscribers and by spam filters).

The best way to avoid being marked as spam is to:

  • Get consent—Make sure people know they’re opting into your email list when they sign up on any of your forms.

  • Send relevant content—This increases your email’s engagement, telling spam filters that you don’t belong in the junk folder. One way to send hyper-relevant content is to segment your subscriber list based on preferences and interests. And don’t forget to personalize your emails.

  • Make it easy to find your unsubscribe link or button.

  • Use both text and images in your emails—Include more text than images!

  • Watch out for spam words in your subject lines and email body.

  • Send your emails from a custom domain—This tells subscribers and spam filters you and your emails are legit. Plus, they look nice :)

If your subscribers are eager to get your emails filled with valuable, beautifully designed content, they won't mark it as spam.

More to learn:

If you need technical assistance, please submit a support ticket via email at support[at] mentioning your Flodesk account login email with a detailed description of your problem.

Did this answer your question?