Help! Why are my emails going to spam?

“Why are my emails going to spam?” This is a question you’ve probably asked yourself on many occasions. If it serves as any consolation, B2B Inbox placement can be as low as 68% according to Validity’s Benchmark report, and on average 1 out 6 legitimate, permission-based emails don’t reach your user's inbox. It’s probably no help that the main email service providers like Gmail, Outlook, and Yahoo continue to make their spam filters stricter, making it trickier for you to reach your customers.

The good news? Below we’ll share all the insights that will help you identify the core reasons why your emails are ending up in the spam folder, and the measures you can take to prevent it. 

Whether you're struggling with cold sales outreach, marketing sequences, or even those all-important transactional emails, by the end of this article you’ll never have to ask yourself again “Why are my emails not sending?” instead will have the knowledge and tools to help you prevent it from happening in the first place.

Table of contents:

• 8 Common Reasons Why Emails Go to Spam
• How Spam Filters Work
• 7 Best Practices to Avoid the Spam Folder
• Tools and Techniques to Test Email Deliverability
• Final steps for keeping your emails out of spam

8 Common Reasons Why Emails Go to Spam

The first step to fixing the issue is understanding why your emails are being flagged as spam. Here are some of the common reasons behind this problem.

1. Poor Sender Reputation

One of the leading causes of emails going to spam is a poor sender reputation. ESPs (Email Service Providers) use a score to measure the reputation of your email domain and IP address. 

If you’ve been flagged for spamming in the past, or if your domain frequently sends emails to inactive or invalid addresses, your reputation may take a hit. This could cause your emails to be sent to spam, even if your content is relevant and well-crafted. Maintaining a good sender reputation is essential to ensuring your emails don’t get blocked or filtered out.

2. Incorrect Email Authentication

Authentication issues are another common reason why emails end up in the spam folder. If your emails lack proper authentication—such as SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), or DMARC (Domain-based Message Authentication, Reporting, and Conformance) —spam filters may be unable to verify that your emails are legitimate. 

This leads them to err on the side of caution and mark your messages as spam. Ensuring your emails are properly authenticated can significantly improve your chances of making it into the inbox.

Source: How to setup DMARC in Office 365

3. Poor Engagement

Even if your emails reach the inbox, negative engagement from recipients can hurt your deliverability in the future. When recipients mark your emails as spam or consistently ignore them, this sends a signal to ESPs that your messages aren’t valuable. 

High rates of unsubscribes, low engagement rates, and negative feedback can contribute to your emails being marked as spam. It’s crucial to create content that resonates with your audience to maintain strong engagement.

4. Content Issues

Sometimes, the content of your email itself triggers spam filters. For example, using certain “spam trigger” words in subject lines or body content can raise red flags. Additionally, emails overloaded with images, links, or broken HTML can appear suspicious to spam filters. Following HTML best practices and maintaining a balance between text and visuals can help your emails appear more trustworthy. A well-structured, concise email is more likely to reach the inbox – 

5. No Unsubscribe Link

This one may sound like a no-brainer, but it can be easily missed! One of the quickest ways to get flagged as spam is by neglecting to include an unsubscribe link in your emails. Spam regulations, like the CAN-SPAM Act, require that all marketing and sales emails provide an easy way for recipients to opt-out. 

If you don’t include this link, your emails will not only frustrate your recipients but they’ll also be flagged as non-compliant, leading to them being filtered into spam folders.

6. Too Many Inactive Users

Sending emails to inactive users—those who haven’t engaged with your emails in a long time—can hurt your sender reputation and increase the chances of your emails going to spam. 

If your list contains too many inactive users, spam filters may see this as a sign that your content isn’t relevant or that your email practices are poor. Regularly cleaning your list to remove inactive subscribers can help improve your deliverability.

7. Inconsistent Sending Patterns

Irregular sending patterns can confuse spam filters and hurt your deliverability. For instance, sending a large number of emails one time, and then disappearing for months can make your domain appear suspicious. 

It’s important to maintain consistent sending patterns to help establish trust with both ESPs and your recipients.

8. High Bounce Rates

Finally, high bounce rates can significantly impact your email deliverability. If a large percentage of your emails are bouncing—whether due to invalid email addresses or full inboxes—this tells ESP that your list hygiene isn’t up to par. Consistent bounce rates will flag your domain as a potential spammer, leading to future emails being directed to the spam folder.

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How Spam Filters Work

Now that we’ve covered why your emails might be going to spam, let’s dive into how spam filters actually work. Understanding the mechanisms behind spam filters can give you insight into how to avoid them.

Spam filters use a variety of algorithms to determine whether an email is spam. These algorithms score emails based on several factors, including content, sender reputation, and engagement. 

Spam detection techniques have evolved significantly over the years. In the early days of email, spam filters relied heavily on keyword detection and basic algorithms. 

Many spam filters also use AI and machine learning to improve their accuracy over time. Some filters even rely on fingerprinting—comparing new emails to known spam messages to detect similarities. Providers like Google have shared some insights on how their specific spam filters work.

This means that sending generic, impersonalized mass emails is more likely to get your message flagged as spam.

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7 Best Practices to Avoid the Spam Folder

Now that you understand why your emails are going to spam and how spam filters work, let’s explore some best practices that can help ensure your emails reach your recipients' inboxes.

1. Build and Maintain a Good Sender Reputation

The foundation of good email deliverability is a strong sender reputation. To build and maintain this reputation, avoid sending emails to inactive users, practice good list hygiene, and send relevant, engaging content. Regularly monitor your sender score, using tools like Postmaster (Gmail) or SNDS (Outlook) and take steps to improve it if necessary.

2. Ensure Proper Email Authentication

Email authentication is key to avoiding the spam folder. Implementing SPF, DKIM, and DMARC protocols helps ensure that your emails are recognized as legitimate by spam filters. 

These authentication methods add a layer of trust and security to your emails, making it less likely that they’ll be flagged as spam.

3. Clean Your Email List Regularly

Regularly cleaning your email list is essential for good deliverability. Remove inactive subscribers, and never buy or share email lists. 

Additionally, use tools like the Email Safety Net ™ that check the health of your emails to ensure your list contains only valid, engaged recipients. Keeping your list clean will improve your sender reputation and reduce bounce rates.

4. Craft Engaging Subject Lines and Content

Your subject lines and content should be both engaging and relevant to your audience. Avoid using spammy language, and strike a balance between text, images, and links. 

Ensure that your emails are concise, well-structured, and easy to read, and always include a clear call to action. Additionally, make sure recipients can unsubscribe easily—this not only keeps you compliant with regulations but also helps avoid spam complaints.

Below is an example of a simple, yet attention-grabbing, cold outreach email.

Source: Cognism

5. Maintain Consistent Sending Patterns

Consistency is key when it comes to email-sending patterns. Whether you’re sending daily, weekly, or monthly emails, stick to a regular schedule that your recipients can expect. 

This consistency helps establish trust with ESPs and prevents your emails from being flagged as suspicious.

6. Monitor and Reduce Bounce Rates

Keep a close eye on your bounce rates, and take steps to reduce them when necessary. Regularly update your email list to remove invalid addresses, and avoid sending large batches of emails to unverified or outdated lists. 

A low bounce rate signals to spam filters that your emails are being sent to valid, engaged recipients.

7. Use Double Opt-In for New Subscribers

Using a double opt-in process for new subscribers can help ensure that your list is filled with engaged, interested recipients. With double opt-in, subscribers confirm their email address before being added to your list, which reduces the likelihood of spam complaints and improves your overall deliverability.

On the flip side of obtaining subscribers, it’s also important to offer an easy-out. Offering a one-click unsubscribe link to users not only improves user experience but can also reduce your chances of being marked as spam.

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Tools and Techniques to Test Email Deliverability

Finally, there are several tools and techniques you can use to test your email deliverability and improve your chances of reaching the inbox. 

Here are the top 3 tools we recommend investing in to stop your emails going to spam:

1. Inbox placement tools - these provide insights into where your emails are landing, as well as spam content checkers that flag any potential issues in your email content. These tools can help you identify problems before you hit “send,” giving you the best possible chance of avoiding the spam folder.

2. Email deliverability and testing software - Email deliverability tools help ensure your emails land in your recipient’s primary inbox and avoid bouncing back. Using software focused on email deliverability can boost your sender reputation, provide valuable insights on spam reports, and help measure the success of your outreach campaigns.

3. Spam content checkers - Spam checkers analyze the content of your email and give you insights into how likely it is to be flagged as spam. They scan your message for spam trigger words, suspicious links, and formatting issues that might raise red flags with spam filters - helping to improve your chances of reaching the inbox.

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Final steps for keeping your emails out of spam

Email deliverability can be a tricky issue, but by understanding the common causes of emails going to spam and implementing best practices, you can improve your chances of reaching your audience - never again ask yourself ‘Why are my emails going to spam?’

Remember, building a strong sender reputation, ensuring proper authentication, crafting engaging content, and maintaining good list hygiene are all essential components of a successful email marketing strategy. 

Take the time to test your emails before sending them, and stay consistent in your outreach efforts. 

Ready to overcome spam filters and get your emails seen by the right people? Why not try Allegrow? You can request an overview here.

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