How to Prevent Emails from Going to Spam

Why Legitimate Emails Sometimes Go to Spam

Before I explain how to prevent emails from going to spam, I believe that it's important for you to understand why legitimate messages are sometimes flagged as malicious. After all, you wouldn't need to implement the solutions described in this article if that wasn't the case.

The main cause of message misclassification issues are spam filters, which are employed by every major mail service provider to protect users from unwanted or potentially harmful messages. As effective as they are, spam filters do occasionally get it wrong despite the use of machine learning and other sophisticated techniques.

The good news is that you're not entirely at the mercy of mail filtering algorithms. You can largely prevent emails from going to spam in Gmail, Outlook, Yahoo, and other virtually all other services by adhering to the best practices described in this article, such as regular mail list cleaning using tools like Verified Email.

How to Avoid Email Going to Spam: 5 Solutions

There are many solutions that you can implement to keep emails from going to spam, and you've probably tried at least one already. The reason why we've selected these five specific solutions is that they've already reliably delivered great results for me, and I firmly believe that they'll do the same for you.

1. Set Up SPF, DKIM, and DMARC Authentication Protocols

Importance: Critical

Ease of implementation: Technical

What would you do if you received a letter with no identifiable information about the sender? Chances are, you'd be hesitant to open it, and it might even end up in the trash. Similarly, emails without proper authentication are far more likely to be flagged as spam or rejected outright by email providers because there's no way to check their authenticity, something the senders of phishing emails like to take advantage of.

To make it possible for others to check that your messages have really been sent by you, it's important to set up the following three authentication protocols:

• SPF (Sender Policy Framework): This protocol verifies that the sending server is authorized to send emails on behalf of your domain.
• DKIM (DomainKeys Identified Mail): DKIM adds a digital signature to your emails, confirming that they haven't been tampered with during transit.
• DMARC (Domain-based Message Authentication, Reporting, and Conformance): Provides instructions on how to handle emails that fail authentication.

The exact setup process for these protocols depends on your email service provider. Most major providers offer step-by-step guides that you can follow, for example:

• Google Workspace
• Microsoft Outlook
• Zoho Mail

Generally, setting up these protocols involves editing your domain's DNS records. Specifically, you'll need to add specific TXT records that contain information about your authorized email servers and authentication policies.

2. Clean Your Mail List Using an Address Verification Service

Importance: High

Ease of implementation: Straightforward

Anyone who is regularly sending messages in bulk to a list of addresses should be equipped with an address verification service. Why? Because addresses can become invalid or inactive over time and messages sent to them turn into hard or soft bounces.

When too many hard or soft bounces accumulate, it can severely damage your sender reputation—a major factor evaluated by spam filters. The best email verification services can quickly analyze your list of addresses and remove those that shouldn't be on it.

My verification service of choice is, of course, VerifiedEmail because it offers excellent accuracy, a user-friendly interface, many extra features, and 500 free mail verification credits that let you test it out without paying.

3. Be Very Careful With Attachments

Importance: High

Ease of implementation: Easy

If you're wondering "why are my emails going to spam from time to time?", attachments might be one of the culprits. That's because electronic mail is still the number of malware distribution channel, accounting for 94% of all malware spread around the world.

Naturally, spam filters take attachments very, very seriously—and so should you. Here are some best practices to follow when sending messages with attachments:

• Consider if the attachment is really necessary. If you can include the file as a link to your website or cloud storage, then do it.
• Certain file types like .exe or .zip are more likely to trigger spam filters, so don't send them via mail if you can.
• Large attachments can trigger spam filters and also cause delivery issues since most providers only support attachments that are up to 25 MB large. If you must share large files, use well-known services like Dropbox or Google Drive.

You will be surprised how quickly can more thoughtful use of attachments increase email deliverability.

4. Keep Your Mail Content Simple and Free of Spam Trigger Words

Importance: High

Ease of implementation: Moderate

In addition to attachments, spam filters also analyze the content of your emails to determine their spam rating, which you can think of as a score that indicates how likely your message is to be marked as spam.

To keep it low, you should keep your content simple by using clear, concise language, maintaining a good text-to-image ratio (basically, you don't want to overdo it with images), and avoiding excessive formatting.

You also want to write mail copy that contains as few spam trigger words as possible. Here are some examples, grouped into categories:

• Finances: Jackpot, Winner, Bonus
• Alerts: Virus, Urgent, Expires
• Heath: Viagra, Medicine, Cure

Of course, you can't exactly avoid the word "medicine" if you're, for example, a pharmacy sending out a newsletter about new stock or promotions. In such cases, the goal is to balance the necessary terminology with other best practices to reduce your bounce rate.

5. Never Send a Mail to a Recipient Without Permission

Importance: Critical

Ease of implementation: Straightforward to Technical

Never send an email to a recipient without their explicit permission because laws like CAN-SPAM in the US and GDPR in the EU require explicit consent for commercial emails.

What's more, when recipients receive unsolicited emails, they're likely to manually mark them as spam. This action teaches spam filters to mark similar emails as spam in the future, significantly impacting your deliverability.

The solution is to implement a double opt-in process that works something like this:

1. 1. Sign-up: The user provides their email address.
2. 2. Confirmation: Send an email with a link to confirm their subscription.
3. 3. Verification: The user clicks the link to confirm, ensuring they genuinely want to receive your emails.

The ease of implementation depends on your specific needs. Many email marketing platforms have built-in double opt-in functionality, but if you're using a custom-built website or an in-house CMS, you may need to develop a custom solution, which requires more time and technical expertise.

Checklist to Prevent Emails from Going to Spam

Here's a quick checklist based on this article to help you prevent messages from going to spam and improve your email deliverability:

• Set up SPF, DKIM, and DMARC authentication protocols
• Clean your mailing list using an address verification service like VerifiedEmail
• Consider if the attachment is necessary
• Avoid sending file types like .exe or .zip
• Use well-known services like Dropbox or Google Drive for large files
• Use clear, concise language
• Maintain a good text-to-image ratio
• Avoid excessive formatting
• Avoid spam trigger words
• Implement a double opt-in process

Conclusion

Preventing messages from going to spam is an essential aspect of email marketing. Solutions like regularly cleaning your email list with a reliable service like VerifiedEmail or setting up proper authentication protocols can significantly improve your deliverability and, with it, the chance of your messages reaching their intended recipients.

For more in-depth information on how to stop emails going to spam and improve your email marketing performance, check out our comprehensive email deliverability guide.