8 min read

Why Does Email Go to Spam? Here Are 14 Reasons and How to Avoid Them

Ever wondered why does email go to spam? Uncover the 14 critical reasons your emails end up in spam folders and how to navigate spam filters and trigger words
Written by
Harsh P
Published on
March 15, 2024

Introduction to Email Deliverability

Email deliverability is crucial for maintaining effective communication with your audience. When emails end up in the spam folder instead of the inbox, it can significantly impact your engagement rates and overall success. But why does email go to spam, and how can we prevent this from happening?

What is Spam? An Overview

What is Spam
What is Spam? An Overview

Spam refers to unsolicited, often irrelevant messages sent over the internet, primarily to a large number of users, for the purposes of advertising, phishing, spreading malware, and more. It's a challenge for both individuals and organizations, cluttering inboxes and posing security risks.

According to a report by Kaspersky, spam emails accounted for 47.3% of all email traffic in 2020. Such a high volume indicates the pervasive nature of spam and its potential to impact email communication efficiency and cybersecurity.

Beyond cluttering your inbox, spam can lead to serious security issues, including phishing scams and malware distribution, which can compromise personal and organizational data security.

Types of Spam:

  • Email Spam: Bulk emails sent without the recipient's permission.
  • Social Media Spam: Unsolicited messages or posts on social media platforms.
  • SMS Spam: Unwanted text messages sent to mobile devices.

What Are Spam Filters and How Do They Work?

What Are Spam Filters and How Do They Work?
What Are Spam Filters and How Do They Work?

Spam filters are tools used by email services to detect unsolicited, unwanted, or harmful emails and prevent them from reaching the inbox. They play a critical role in maintaining the integrity and usability of email communication.

Detection Methods:

  • Content Analysis: Scans for known spam trigger words or phrases.
  • Header Analysis: Looks for discrepancies or anomalies in the email's source information.
  • Blacklists: Blocks emails from known spam sources.
  • Authentication Checks: Verifies SPF, DKIM, and DMARC records to confirm the email's legitimacy.

Effectiveness and Challenges:

While highly effective, spam filters aren't foolproof. They can sometimes flag legitimate emails as spam (false positives) or miss actual spam emails (false negatives).

The continuous evolution of spam techniques means that spam filters must also adapt. Machine learning and AI are increasingly being employed to enhance the accuracy of spam detection.

Why Spam Filters are Essential:

They protect users from potentially harmful content and help maintain the productivity by keeping inboxes clean and focused.

In 2019, it was estimated that spam filters saved businesses approximately $1 billion annually by reducing the time employees spent managing unwanted emails.

Email Service Provider Filters

Gmail Spam Filter: Google's proprietary spam filtering technology, which uses sophisticated algorithms and machine learning to identify and filter out spam emails.

Outlook/Hotmail Filter: Microsoft's email filtering system, incorporating user feedback, authentication checks, and pattern analysis to prevent spam.

Yahoo Mail Spam Filter: Utilizes a combination of user-defined rules and Yahoo's own spam detection technology to keep unwanted emails out of the inbox.

14 Reasons Why Your Emails Go to Spam Folder and How to Avoid Them

Email deliverability is a complex process influenced by various factors. Understanding why emails end up in the spam folder can help you adjust your strategies and ensure your messages reach your audience. Here are two key reasons based on the keywords provided:

1. Poor Sender Reputation

Poor Sender Reputation
Poor Sender Reputation

Sender reputation is a score assigned to your sending domain by Internet Service Providers (ISPs) and email services. It reflects the trustworthiness of your emails based on your sending habits, the quality of your content, and how recipients interact with your emails.

Why Emails Go to Spam

A poor sender reputation suggests to ISPs that your emails are not valued by recipients, possibly due to previous spam complaints, high bounce rates, or low engagement. ISPs are more likely to filter emails from low-reputation senders directly to the spam folder to protect their users.

How to Avoid:

  • Monitor Your Sender Score: Tools like provide insights into your current reputation.
  • Improve Engagement: Regularly clean your list to remove inactive subscribers and tailor your content to increase open and click-through rates.
  • Follow Best Practices: Ensure you're only sending emails to users who have explicitly opted in. Regularly check for and remove hard bounces (invalid email addresses).

2. Spam Trigger Words

Spam Trigger Words
Spam Trigger Words

Spam trigger words are specific words or phrases that are commonly associated with spam emails. These include overly promotional phrases like "Buy now," "Free," "Guaranteed," or "Urgent."

Why Emails Go to Spam

Email services and spam filters use sophisticated algorithms to scan email content for these trigger words. Emails that contain a high number of these phrases are more likely to be marked as spam since they resemble typical unsolicited content.

How to Avoid:

  • Carefully Craft Your Content: Avoid using aggressive sales language and focus on providing value in your emails. Use natural language that speaks directly to your audience's needs and interests.
  • Use A/B Testing: Test different versions of your content to see which are less likely to trigger spam filters. This can help you understand which phrases to avoid.
  • Stay Updated: The list of trigger words can change as spam filters become more sophisticated. Keep up with email marketing best practices to ensure your content remains effective.

3. Low Engagement

Low Engagement
Low Engagement

Low engagement refers to situations where recipients do not often open, read, or interact with the emails you send. This includes low open rates and click-through rates, which can signal to email service providers that your content may not be relevant or welcomed by your audience.

Impact on Deliverability:

Email service providers use engagement metrics as a key factor in determining email deliverability. Low engagement can lead to your emails being directed to the spam folder, as it suggests to spam filters that recipients are not interested in your messages.

According to a study by Mailchimp, the average open rate across all industries is around 21.33%. Falling significantly below this benchmark can trigger spam filters to evaluate your emails more critically.

Strategies to Improve Engagement:

  • Personalization: Use the recipient's name and tailor content based on their interests and past interactions.
  • Segmentation: Divide your email list into segments based on demographics, behavior, or purchase history to send more targeted and relevant emails.
  • A/B Testing: Test different subject lines, email content, and send times to discover what resonates best with your audience.

4. Not Including an Unsubscribe Link

Not Including an Unsubscribe Link
Not Including an Unsubscribe Link

The absence of a clear and easy-to-use unsubscribe link in your emails not only violates email marketing regulations, such as the CAN-SPAM Act, but also negatively impacts your sender reputation. Recipients who cannot easily unsubscribe from unwanted emails may resort to marking your emails as spam, which can harm your deliverability rates.

Legal and Reputation Implications

The CAN-SPAM Act requires that all commercial emails provide a clear mechanism for recipients to opt-out of future emails. Failure to comply can result in hefty fines.

When recipients mark your email as spam because they can't find an unsubscribe link, this signals to email providers that your emails may be unsolicited, further degrading your sender reputation.

Best Practices for Unsubscribe Links

  • Visibility: Ensure the unsubscribe link is easy to find, typically in the footer of your email.
  • Simplicity: The unsubscribe process should be straightforward, requiring no more than a click or two.
  • Immediate Action: Process unsubscribe requests promptly to avoid sending more unwanted emails, which could lead to more spam complaints.

5. Lack of Email Authentication

Lack of Email Authentication
Lack of Email Authentication

Email authentication involves setting up protocols such as SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting, and Conformance) to verify that the sender is authorized to send emails on behalf of a domain.

A lack of these authentication measures can significantly increase the likelihood of your emails being flagged as spam.

Why It's Critical

Email service providers use these authentication standards to prevent spoofing, phishing, and to ensure that the email genuinely originates from the claimed domain. Without these measures in place, your emails might be considered untrustworthy or fraudulent, directing them straight to the spam folders.

A study by Return Path indicates that emails with proper DMARC policy have a 10% higher deliverability rate compared to emails without.

Implementing Authentication

  • SPF Records: Ensure your domain’s DNS settings include an SPF record that lists all the IP addresses authorized to send emails on behalf of your domain.
  • DKIM Signatures: Implement DKIM by attaching a digital signature to each email, which can be verified against a public key in your DNS records.
  • DMARC Policy: Set up a DMARC policy to instruct email providers on how to handle emails that fail SPF or DKIM checks, adding an additional layer of security and trust.

6. Inconsistent Sending Volumes

Inconsistent Sending Volumes
Inconsistent Sending Volumes

Inconsistent sending volumes, such as sending very high volumes of emails sporadically or after a period of inactivity, can trigger spam filters. Email providers monitor sending patterns and abrupt changes can raise suspicions of spamming activities.

Impact on Reputation

Sudden spikes in email volume can be interpreted as spamming behavior, affecting your sender reputation. Maintaining a consistent sending schedule helps in building a positive reputation with ISPs and reducing the chances of being flagged as spam.

For instance, a study by IBM noted that maintaining regular communication with your audience can improve open rates by up to 40%, as recipients become accustomed to your sending patterns.

Maintaining Consistency

  • Schedule Regular Sends: Establish and adhere to a consistent email sending schedule, whether it’s weekly, bi-weekly, or monthly.
  • Gradual Increase: If you need to increase your sending volume, do so gradually over time to avoid alarming spam filters and recipients alike.
  • Audience Engagement: Regularly engage with your audience to keep open and click-through rates steady, which in turn supports a stable sending volume.

7. Using “No-Reply” in the Sender’s Email Address

Using “No-Reply” in the Sender’s Email Address
Using “No-Reply” in the Sender’s Email Address

Incorporating “No-Reply” in the sender’s email address can be detrimental to your email marketing efforts for several reasons. This practice can discourage engagement and create a perception of unapproachability, leading recipients to ignore the emails or mark them as spam.

Impact on Recipient Engagement:

A "No-Reply" sender address sends a message that feedback or replies are not welcomed, which can diminish the user experience and engagement. Engagement is a critical factor used by email service providers to determine an email's placement in the inbox or spam folder.

Data from various email marketing platforms indicate that emails perceived as one-way communications have lower engagement rates, which can negatively affect your overall email deliverability.

Strategies to Encourage Engagement:

  • Use a Friendly, Branded Email Address: Opt for sender email addresses that are welcoming and recognizable to your audience, encouraging them to engage with your content.
  • Invite Feedback: Include calls-to-action in your emails that encourage recipients to reply with questions, feedback, or preferences, demonstrating that you value their input and interaction.

8. Misleading Subject Lines

Misleading Subject Lines
Misleading Subject Lines

Misleading subject lines not only erode trust between you and your recipients but also violate email marketing regulations like the CAN-SPAM Act. Subject lines that promise one thing but deliver another can frustrate recipients, leading to increased spam complaints and negatively affecting your sender reputation.

Legal and Trust Implications:

Misleading subject lines are explicitly prohibited under laws like the CAN-SPAM Act, which mandates honesty in email communication. Violations can result in significant fines and legal repercussions.

A study showed that emails with clear and honest subject lines have open rates as much as 50% higher than those perceived as misleading, highlighting the importance of trust in improving email engagement and deliverability.

Best Practices for Subject Lines:

  • Be Clear and Direct: Ensure your subject line accurately reflects the content of your email. This clarity helps set the right expectations and builds trust with your audience.
  • Test and Optimize: Utilize A/B testing to find the most effective subject lines for your audience. This data-driven approach can help you understand what resonates best and fosters positive engagement.

9. Sending to Many Invalid Email Addresses

Sending to Many Invalid Email Addresses
Sending to Many Invalid Email Addresses

Sending emails to numerous invalid or non-existent email addresses can significantly harm your email deliverability and sender reputation. Email service providers track bounce rates as an indicator of list quality and sender reliability.

Impact on Sender Reputation:

High bounce rates are a red flag for email service providers, indicating that the sender may not be maintaining a clean email list. This can lead to emails being more frequently directed to spam folders. A bounce rate above 2% is often considered problematic.

According to a 2022 report, maintaining a bounce rate below this threshold is crucial for preserving sender reputation and ensuring emails reach the inbox.

Strategies for Maintaining List Hygiene:

  • Regular List Cleaning: Use email verification tools to identify and remove invalid email addresses from your list regularly.
  • Double Opt-In: Implement a double opt-in process for new subscribers. This method ensures that the email address is valid and that the owner wishes to receive your communications.

10. Use of Free Sender Domains

Use of Free Sender Domains
Use of Free Sender Domains

Using free email domains (such as Gmail, Yahoo, or Outlook) for sending business or bulk emails can also negatively impact your deliverability and professionalism. Email service providers may scrutinize emails from these domains more closely, due to their common use in spam and phishing attempts.

Perception and Deliverability Issues:

Sending from a free domain may signal to recipients and email services that the sender is not a legitimate business, potentially decreasing trust and increasing the likelihood of emails being marked as spam.

A study has shown that emails sent from professional domain addresses have a higher deliverability rate by approximately 15% compared to those sent from free email service providers.

Advantages of a Professional Email Domain:

  • Increased Credibility and Brand Visibility: A professional email address that includes your business domain reinforces your brand identity and enhances credibility with your audience.
  • Improved Deliverability: Emails from a business domain are less likely to be flagged by spam filters, assuming other best practices are also followed.

11. Poor List Hygiene

Poor List Hygiene
Poor List Hygiene

Poor list hygiene refers to the practice of not regularly cleaning and updating your email list. This includes failing to remove unsubscribed, inactive, or invalid email addresses, which can lead to increased bounce rates, higher spam complaints, and diminished sender reputation.

Consequences of Neglecting List Hygiene:

An unclean email list can significantly impact your email campaign's performance, with increased chances of your emails being flagged as spam. For example, a high number of inactive subscribers can skew your engagement metrics, misleading your strategy.

Studies have shown that regularly cleaning your email list can improve open rates by up to 20%, as it ensures your emails are being sent to engaged and interested recipients.

Best Practices for List Hygiene:

  • Regular Monitoring and Cleaning: Actively remove non-engaging, bounced, and unsubscribed email addresses from your list.
  • Re-engagement Campaigns: Periodically send re-engagement emails to inactive subscribers to confirm their interest in receiving your communications. This helps in maintaining a highly engaged audience.

12. Email Spoofing and Phishing

Email Spoofing and Phishing
Email Spoofing and Phishing

Email spoofing and phishing involve the forgery of email headers or the sending of deceptive emails, respectively, to trick recipients into believing the email is from a legitimate source.

These practices not only harm recipients but can also tarnish the perceived integrity and security of your domain if it's being spoofed.

Impact on Trust and Security:

When attackers spoof your domain to send phishing emails, it can lead to a loss of trust among your audience, damaging your brand reputation and email deliverability. Email providers may begin to flag all emails from your domain as suspicious, affecting even legitimate communications.

The FBI’s Internet Crime Complaint Center reported that losses from phishing and similar fraud totaled over $4.2 billion in 2020, highlighting the critical need for businesses to protect their domains from being used in such attacks.

Strategies to Combat Spoofing and Phishing:

  • Implement Email Authentication Protocols: Setting up SPF, DKIM, and DMARC records for your domain can help prevent spoofing by verifying that the sender is authorized to use your domain, thus protecting your domain's integrity.
  • Educate Your Audience: Inform your subscribers about the possibility of phishing attempts and advise them on how to verify the authenticity of the emails they receive from your brand.

13. Failure to Use a Recognizable From Name

 Failure to Use a Recognizable From Name
Failure to Use a Recognizable From Name

Not using a recognizable from name in your email campaigns can significantly impact your open rates and overall email deliverability. This factor plays a crucial role in how recipients perceive and interact with your emails.

Impact on Recipient Trust:

A recognizable from name builds trust and recognition among your audience. When recipients can't immediately identify who the email is from, they are more likely to ignore the message or mark it as spam. According to marketing studies, using a consistent, recognizable from name can increase open rates by up to 35%.

Strategies for Enhancing Recognition:

  • Brand Consistency: Use your brand name or a well-known person from your organization as the from name to ensure recipients recognize the sender.
  • Personalization and Familiarity: In some cases, personalizing the from name to include a specific contact from your company who the recipient has interacted with can further improve open rates.

14. HTML Errors or Overuse of Images

HTML Errors or Overuse of Images
HTML Errors or Overuse of Images

Emails that are poorly coded or rely heavily on images can face deliverability issues. Spam filters may flag such emails, and they may not render correctly across all email clients, affecting the user experience.

Impact on Spam Filters and User Experience:

HTML errors can trigger spam filters, as they are often associated with phishing attempts or poorly constructed spam emails.

Moreover, emails that consist predominantly of images with little to no text may not only trigger spam filters but also fail to convey the message if images are blocked by the recipient's email client.

Research indicates that emails with a balanced text-to-image ratio and clean HTML code have a higher chance of avoiding spam filters and are more accessible to a wider audience, improving engagement rates.

Best Practices for Email Design:

  • Optimize Text-to-Image Ratio: Aim for a balance between text and images to ensure your message is delivered effectively, even if images are not displayed.
  • Validate HTML Code: Use email design tools that provide clean HTML output or manually check your code for errors to avoid deliverability issues.
  • Accessibility and Alt Text: Ensure all images include alt text so the message is clear even if the images aren’t displayed, enhancing accessibility for all recipients.

How Do I Know If My Email Is Going to Spam?

How Do I Know If My Email Is Going to Spam?
How Do I Know If My Email Is Going to Spam?

Determining whether your emails are landing in spam folders is crucial for assessing and improving your email marketing strategy's effectiveness. Recognizing the signs can help you take corrective actions to ensure your messages reach your audience's inbox.

Monitoring Open Rates

Monitoring Open Rates
Monitoring Open Rates

A significant drop in open rates can be a red flag. For instance, if your industry's average open rate is around 20% and you're seeing numbers significantly lower, it might indicate that your emails are going to spam.

Open rates offer a quick snapshot of how many people are actually seeing and opening your emails. A sudden decrease could signal deliverability issues.

Utilize your email marketing platform's analytics tools to track and compare your open rates over time.

Checking Your Spam Score

Checking Your Spam Score
Checking Your Spam Score

Before sending out a campaign, use tools to check your email's spam score. This score helps predict how likely your email is to be marked as spam.

A high spam score indicates that something in your email's content, setup, or sending domain is raising red flags with spam filters.

Services like Mail-Tester offer insights into your spam score and provide actionable feedback on how to lower it.

Reviewing Bounce Rates

Reviewing Bounce Rates
Reviewing Bounce Rates

An increase in bounce rates, especially hard bounces (permanent failures), can indicate that your emails are being rejected by servers, possibly due to being flagged as spam.

High bounce rates can affect your sender reputation, leading to more emails being filtered as spam.

Analyze the bounce reports provided by your email service provider for insights into the nature and volume of bounces.

Asking Your Audience

Directly asking subscribers if they're receiving your emails can provide clear evidence. This can be done through alternative communication channels like social media.

Feedback from your audience can give you the most direct insight into whether your emails are reaching their intended destination.

Conduct a poll or ask for feedback on social media platforms or through direct communication tools like SMS.

Using Seed Testing

Seed testing involves sending your email to a list of test accounts (seeds) across different email providers to see where your email lands.

This method allows you to see firsthand how different email services treat your emails, providing a comprehensive view of deliverability issues across the board.

Create accounts on major email platforms (like Gmail, Yahoo, Outlook, etc.) and add them to your seed list. Send your campaign to this list and check where your email lands in each account.

Understanding the CAN-SPAM Act to Avoid Spam Folders

Understanding the CAN-SPAM Act to Avoid Spam Folders
Understanding the CAN-SPAM Act to Avoid Spam Folders

This Act sets the rules for commercial email and messages, establishes requirements for commercial messages, gives recipients the right to have you stop emailing them, and spells out tough penalties for violations. By adhering to the CAN-SPAM Act's guidelines, you can avoid triggering alert spam filters, thus ensuring your marketing emails reach the recipient's inbox rather than getting diverted to the recipient's spam folder.

Key Provisions of the CAN-SPAM Act

Provide a Clear Way to Opt-Out

Provide a Clear Way to Opt-Out
Provide a Clear Way to Opt-Out

Every email must contain a clear and conspicuous explanation of how the recipient can opt out of getting email from you in the future. Honor opt-out requests promptly, within 10 business days.

Include Your Physical Address

Each email must include your valid physical postal address. This can be your current street address, a post office box you've registered with the U.S. Postal Service, or a private mailbox you've registered with a commercial mail receiving agency established under Postal Service regulations.

Avoid Misleading Header Information

The "From," "To," "Reply-To," and routing information – including the originating domain name and email address – must be accurate and identify the person or business who initiated the message.

Don’t Use Deceptive Subject Lines

The subject line must accurately reflect the content of the message. Misleading subject lines can lead to emails going to spam, as they violate trust and can trigger recipient complaints.

Identify the Message as an Ad

Identify the Message as an Ad
Identify the Message as an Ad

The law gives you a lot of leeway in how to do this, but you must disclose clearly and conspicuously that your message is an advertisement.

How Compliance Can Avoid Spam Filters

How Compliance Can Avoid Spam Filters
How Compliance Can Avoid Spam Filters

Building Trust with Recipients

By following CAN-SPAM Act guidelines, you establish a foundation of trust with your recipients. This trust can lead to higher engagement rates, as recipients feel more comfortable opening and interacting with your emails, knowing they contain no misleading information and offer a simple way to unsubscribe.

Reducing Spam Complaints

Compliance with the Act reduces the likelihood of recipients marking your emails as spam. Fewer spam complaints contribute to a better sender reputation, decreasing the chances of your emails being automatically filtered into the spam folder by email service providers.

Enhancing Deliverability through Transparency

Including a physical address and clear identification of your message as an advertisement promotes transparency. This transparency not only complies with legal requirements but also reassures email service providers that you're a legitimate sender adhering to best practices, making them less likely to flag your emails as spam.

Practical Steps for Compliance

Regularly Audit Your Email Practices

Ensure all aspects of your email marketing comply with the CAN-SPAM Act. Regular audits can help identify potential areas of non-compliance.

Educate Your Team

Make sure everyone involved in email marketing understands the importance of compliance with the CAN-SPAM Act and how to implement it in your emails.

Monitor Engagement and Adjust Accordingly

Keep an eye on how changes to your email practices affect engagement. If you notice a drop in open rates or an increase in unsubscribes, reassess your strategy to ensure it aligns with both legal requirements and your audience's preferences.

Concluding Thoughts

To avoid your emails landing in spam, focus on these key actions: keep your email list clean, use clear and honest subject lines, make sure your emails are technically set up right (like using SPF and DKIM), and always include an unsubscribe link.

Remember to send emails people want to receive and stay away from tactics that look spammy. By following these simple steps, you'll improve your chances of hitting the inbox and keep your communication effective.

What is Alore?

Email Warmer

Generate real engagement to Warm Up Your Email Address without any human intervention

Drip Campaigner

Send emails that generate new business opprotunities for you

Collaborative Inbox

Improve team performance & customer experience - manage multiple email addresses from one place