9 Reasons Why Your Emails Land in Spam and What You Can Do About it

spam reasons and spam filters

Emails have become an essential part of the present digital life we live in. There are about 4 billion people using emails across the globe. Whether you are a starter or a professional marketer, you sure must have at some point or the other faced issues that include emails landing in the “SPAM” folder instead of the “INBOX”. Businesses that are highly dependent on sending bulk emails are more prone to getting penalized by email service providers.

Have you ever tried to find out why your emails are landing in the spam folder and not reaching the inbox? Do not sweat. In this blog, you will learn everything about email spam, including why emails land in the spam folder instead of the inbox and how you can stop emails from reaching the spam folder. You will also get some simple solutions you can implement along with some of the best tools to identify the problem.

Table of contents

What is spam?

Spam originated from the word that was coined for canned pork. Suddenly this product was so prominent in the US that TV ads went overboard with their marketing campaigns. Email marketers associated this with those emails which were all over the internet but weren’t relevant and hence they started calling such emails: spam

Spam is any unsolicited email sent in bulk. Sent in bulk is important. Take the example of the guy next door who wants to sell his car and observes that you have a vacant parking lot. If he sends you a one on one email, even though you haven’t given him consent, the email is relevant. The email has been sent with a strategy in mind. However if the same guy sent a bulk email campaign to the entire neighborhood without knowing if any of the users had a vacant parking lot or not, the campaign would be considered spam.

How does an email service provider detect and mark emails as spam?

Do you think only spam emails reach the spam folder? Absolutely no! There is a chance for your emails to land in the spam folder even if you are a trusted business. There are filters and anti-spam software that identify the red flags by scanning emails. And in those scans, if they find anything it considers spam, your emails get flagged as spam.

So let’s understand how anti-spam software and filters detect spam messages. When you start sending emails to your subscribers, it will land in the inbox only after it is verified by the filters.

9 Reasons why your emails land in the spam folder

Is it possible for even my legitimate emails to land in the recipient’s spam? Absolutely yes! Because security measures are smart, and therefore even a small mistake can land your legitimate email in the spam folder.

Here are some critical points stating how emails can land into the spam folder instead of the inbox. These points become especially important when you are sending bulk emails.

1. If you haven’t received permission from the email recipients

It’s important to have an email-centric sign-up flow if you want your email program to do well. Always have a check-box in the sign-up flow which allows users to opt-in for newsletters and promotional emails. Ensure that you are targeting only those users who have opted in for direct marketing alerts.

To know how to use opt-in in your marketing strategy you can read these guides:

How to Use Opt-In in Your Email Marketing Strategy

What Is Double Opt-In and Why You Should Use It

2. When you have a low IP reputation

Your IP address gets shared whenever you send an email. Sharing an IP number has many drawbacks. If your IP has a negative reputation from the current or previous senders with poor habits, it can be the reason for your email landing in the spam.

Ensure that you are managing your IP reputation well. Google & Hotmail have their postmaster tools which allow you to track the IP reputation. You must make sure that if you have allotted a shared IP pool, only clients with good mailing practices are sharing the IP pool so that the mailing by one brand doesn’t affect the other brand.

3. When you have a low domain reputation

Domain reputation is important for email deliverability. When the domain reputation is high, you automatically receive good deliverability. Email volume increasing inconsistently is another primary reason for your emails to land in the spam folder.

4. When you have poor email design and irrelevant content

If your content is irrelevant to the recipient, it's likely that the recipient will engage negatively with the email even if you manage to reach the inbox. Moreover, when you use too many images, links, and less text, your message appears to be spammy, which is a clear red flag for the spam filters.

Also, most of the spam filters are AI-based. If the content has had a history of hitting spam, even if you have changed the entire email headers, the chances of hitting the inbox are very minimal.

5. When you receive negative engagements

Negative engagement means your emails are being reported as spam. Spam complaints should be minimized as far as possible. Even with high open rates, if users open your emails to report spam, the reputation will come down and you will start hitting the spam box more frequently. Hence getting the strategy right-targeting the right users at the right time with the right content is important.

6. When you have HTML issues

If your email has different HTML versions, broken HTML, or even a plain text version, it will automatically reach the spam folder. When you have broken HTML, it starts appearing unreadable and sloppy on every email client. Your users will start marking your emails as spam too when they see broken HTML.

7. When your email authentication fails

If you have been passing SPF & DKIM and suddenly they start failing due to some configuration issue or DNS failure, the emails have a very high chance of landing in spam. Hence it’s necessary to keep an on all authentication protocols while you are monitoring your infrastructure.

Imagine you are sending an email to a recipient with little interest in your product. Naturally, they’d want to unsubscribe from getting further emails. But if you don’t have an unsubscribe button in the email, there are chances that the recipient will report your email as spam, which we already know is a negative trend.

9. The proportion of active users

It’s imperative that you maintain a balance between active and inactive users in your mailing list. The percentage of active users needs to outweigh the percentage of inactive users. If inactive users start outweighing the active users, your emails would start landing in spam.

How to avoid emails landing in the spam folder with a best practices checklist

There are many reasons for emails landing in the spam folder. Some of them are email authentication status, diligence in analyzing the email metrics, email list health, the value you offer your recipient with your email content, etc. A few tips you can use to keep your emails out of the spam folders are:

1. Building your own email list

You need to be aware of the messages you send to your targeted audience. In case you are sending the wrong message to your targeted audience or using the right message to an unengaged audience, both are considered to be a waste of time and will send your IP address to the spam list.

Ensure you avoid the following.

  • Using a shared list

  • Co-registering, purchasing, or renting email from a third party. When you do email harvesting or scrap emails, you get added to the spam camp.

If you need a long-term benefit with an email program, you need to build your email list organically. Developing a trustworthy plan is not an easy task but once you have sketched one, you don't have to worry about longevity.

2. DMARC, DKIM, and SPF – Email authentication with any one of them

Though authentication of your email is tricky, it can bring many benefits when sending a legitimate email. Yahoo, Google, and other inbox providers prioritize authenticated email, and therefore your email directly reaches the inbox instead of the spam folder.

  • DMARC (Domain-Based Message Authentication Reporting and Conformance) influences the power of DKIM and SPF.

  • DKIM (Domain Keys Identified Mail), when you meet this standard, you can make sure that there are no chances of email tampering during transmission.

  • SPF (Sender Policy Framework) checks who you are by comparing the sender's IP with a list of IPs authorized by the domain administrators.

3. Monitoring reputation by avoiding deny lists

You will be on the email deny list( (blacklist) if your email domain reputation slips or when you send an email to any of the spam trap emails. There is even a chance for the well-intentioned and cautious senders to fall into the email deny list.

Below are few best practices you should follow to reduce this risk of falling into the email deny list:

  • Making use of the real-time email address validation.

  • Remove unengaged subscribers by implementing a sunset policy. Sunset policy is the practice of getting inactive users out of your mailing list.

4. Monitoring the engagement metrics of your emails

You can quickly know if any changes are needed in your email or if your email program is improving by tracking the engagement metrics and email performance. You can also build a few baseline metrics to have a clear picture of the email performance. Click-through rates, open rates, and spam complaints are some of the metrics that can be followed.

5. Improving your email design, content, structure

There are many practices to follow while you design an email. Few are as follows:

  • It’s easy for people to recognize you when your email is in line with the brand. It includes things like tone, images, fonts, colors, etc.

  • Do not use spam trigger words like “special offer,” “risk-free,” “dear friend,” “toll-free,” and more.

  • Ensure your email texts are to the point, simple, and easily readable for your targeted customers.

  • The email you send needs to be desktop compatible and mobile-friendly.

  • Don’t just include images. Your text and image ratio should balance each other for a perfect email template.

  • In case you are sending a marketing email, your email should contain a physical address.

Read our comprehensive guide on how to improve email design for higher deliverability


A good email engagement rate on your emails has a higher chance to reach the inbox instead of the spam folder. Staying updated on the acceptable practices based on the continually changing email trends will help you to remain safe.

Apart from the above factors, you can also follow the tips given below to land emails directly in the inbox.

Tips to land emails directly in the inbox

  • Take the users’ consent in the sign-up flow. It will help keep your email deliverability and engagement rates high.

  • Performing a full-fledged domain warmup before starting campaigns with a new domain.

  • Asking email users to drag the email from different tabs (like spam, promotions, etc.) to their primary inbox folder.

  • Cleaning your email list regularly will help in stopping the low email engagement rate. Being proactive is essential for receiving improved email deliverability rates.

  • Offering a preference center enables both existing and new subscribers to select how frequently they get your emails. It decreases the risk of your subscribers marking your email as spam. You will also experience higher engagement rates.

  • Asking subscribers to whitelist your email.

Free tools to check if your emails are landing in the spam folder

There are plenty of free tools available online that can help detect deliverability, test your reputation, render the quality of email content, subject lines, and more. But in this blog, we have covered an all-in-one free tool that can do everything without much hassle.

Google Postmaster

Google Postmaster tool is a free email analytics tool that enables businesses to analyze different factors based on email performance. The tool offers senders insights about the email sending practices, problematic areas and provides a solution to enhance deliverability and overall email success rate.

How to activate Google Postmaster tools?

If you are looking to send more than 100,000 email addresses with a larger email size, then visit Google Postmaster tools to follow the verification process. You will be asked to install Google Search Console while activating the tool. You will be able to access information and reports on your domain reputation, spam rate, authentication, delivery errors, IP reputation, feedback loop, and encryption once you set up your account and verify the domain.

There are important factors to understand when it comes to these metrics and data points. They include the following:

  • Google Postmaster tools focus only on messages that are associated successfully with a domain through DKIM or SPF authentication. If an organization does not have an authenticated email with their domain, then Google Postmaster will not be able to access that data.

  • Google Postmaster tool has a minimum email volume threshold for data to populate. Messages to “@gmail.com” users only will be shown in the Google Postmaster Tool metrics and therefore there is no chance for emails that are sent to G Suite or Google Workspace to accrue in the platform.

  • The reports from Google Postmaster will be updated once a day by taking into account the insights of the previous day's performance. Most of the data is populated usually around 7.00 PM UTC or 12:00 PM Pacific. It means there would be a lag in the data availability. When there is a delay, the Google Postmaster tool cannot be used to monitor specific campaign performance.

Start sending a spam-free email marketing campaign with high deliverability

Finding the correct reason for your emails landing in the SPAM folder is complicated. I hope the above guide provides you with a good understanding of email spam and how to make your emails reach the inbox folder. In case you have any queries, feel free to reach out to the team at Mailmodo and we will help you in establishing an impeccable deliverability rate and email conversion.

Bring life to your emails

Convert your emails into experiences
with interactive AMP elements