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, how to avoid emails reaching the spam folder, simple resolutions you can implement along with some of the best tools to identify the problem, and more.

Table of contents

What are spam filters?

Spam filters are standard software that use different filter techniques to stop unwanted emails from reaching the user’s inbox. Some of the filter techniques include spam filtering by content, blacklisting certain IPS, avoiding posting the email ID on the internet publicly, making use of contact forms, and using effective anti-spam solutions.

The spam filters verify based on factors like specific words in the message body or subject, the sender’s email address, and ISPs. Spam filtering occurs at the email server level, email program level, and filters the emails accordingly before it lands in the spam or inbox folder.

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.

Hence, let’s understand how an 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.

Spam Filters

Spam filters will analyze your email and decide whether it satisfies required security measures that include the following security protocols: content filters, permission filters, general blacklist filters, header filters, challenge-response filters, and rule-based filters. If the email satisfies the security measures, it will reach the inbox folder or go straight to the spam folder.

Anti-spam filters

These examine the following in an email: email content, header data, subject line, and more. The header data is also considered as the email GPS. It easily tracks where the email is received, where the email lands, and when it arrives.

Blacklists or Blocklists

Blacklists or blocklists are a list maintained by ISPs that maintain the records of entities that fall under the category of global spammers. The email automatically gets banned once it is identified that one of the listed global spammers is sending the email.

Spammers are smart, and therefore they find tricky ways to deliver the message to the recipients. To prevent this, ISPs mark the email as spam. The filters for inbox providers quickly analyze and identify spam messages, which is vital to keep you safe on the internet.

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 while sending an email can place your legitimate email into 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

Getting approval is mandatory and considered vital to enhance email deliverability. Prefer to choose an opt-in list through an application or website instead of purchasing bulk unreliable email lists. Make it enticing and easy for your targeted customers to join your email list. When you build the recipient list organically, you can easily make emails land directly in the inbox folder.

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 may also be a critical reason for your email landing in the spam. To stop this issue, you can work with some popular email service providers to drive you on the right track. In case you are sending 100,000+ emails for a month, the best idea is to use a dedicated IP address.

3. When you have a low domain reputation

Domain reputation

is critical 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 email content is irrelevant to the recipient there are high chances 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 messages appear to be spammy, which are clear red flags for the spam filters.

5. When you receive negative engagements

When interested and willing people receive your emails, there are many chances for positive engagement. When you have higher reputations, the email will automatically land directly in the inbox instead of spam folders. In case you receive negative engagement, you need to work on that and turn that into positive.

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. In this case, your users will start marking your emails as spam, which will in return alert the spam filters. If your email size is higher than 100 KB, it could also be a reason for your emails landing in the spam folder.

7. When your email authentication fails

If you are making use of any third-party ESPs, email authentication is essential. Your emails get authenticated automatically when you use reputed email service providers like Gmail, Apple Mail, AOL, Yahoo Mail, etc. Other reasons include not adding SPF (Sender Policy Frameworks records), DKIM (DomainKeys Identified Mail), and DMARC records.

Imagine you are sending an email to a recipient with no interest in your product and without an unsubscribe button in the email. In this case, there are high chances that the recipient will report your email as spam. So, it’s essential to have an unsubscribe option in your email so even if your recipients don’t like receiving your emails, they can easily unsubscribe rather than report spam.

9. Other important spam reasons

Apart from the above reasons, there are also some other important reasons for your email directly landing in the spam folder.

  • When you are not clear of what your subscribers need from you.
  • When your email frequency is off.
  • When you are not paying importance to email list hygiene.
  • When you are using malicious tactics to increase your email open rates.

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

There are plenty of reasons for emails landing in the spam folder like email authentication status, diligence in analyzing the email metrics, email list health, the value you offer your recipient with your email content, and more. Check out our tips below to keep your emails out of the spam folders.

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 a 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.

There 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

  • Making use of double-opt-in or confirmed opt-in

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.

  • 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.


When you have a good email engagement rate, your email 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 other tips to land emails directly in the inbox.

Tips to land emails directly in the inbox

  • Ask your users to double opt-in. 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 those 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

Exploring the right 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.

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