Why Emails Go to Spam & How to Fix It

1. Overview

Email filters have become extremely strict. In early 2024, Google and Yahoo introduced new deliverability updates that block custom business domains if they lack basic verification records. If you noticed your sales newsletters or notification emails are suddenly routing directly to the spam folder, the cause is likely technical authentication configuration.

2. Signs & Symptoms

How do you know if your domain has a deliverability problem? Look for these indications:

• Email open rates dropping below 10% (normal averages range between 18-25%).
• Receiving SMTP 550 reject bounce messages when sending mail to @gmail.com or @yahoo.com addresses.
• Subscribers complaining they cannot find your sign-up links, only to discover them in their Junk or Spam folders.

3. Technical Explanation

Spam filters protect users from phishing and spoofing. To verify that an email claiming to be from admin@company.com actually originated from your server, filters look for three key DNS verification records:

• SPF (Sender Policy Framework): Lists the authorized server IP addresses that are allowed to send mail on behalf of your domain.
• DKIM (DomainKeys Identified Mail): Adds a cryptographic signature verification to your email body headers, ensuring the email was not modified in transit.
• DMARC (Domain-based Message Authentication, Reporting, and Conformance): Tells receiving servers what to do if SPF or DKIM checks fail (e.g., monitor, quarantine, or reject).

4. Step-by-Step Fixes

Follow these steps to check and resolve your email authentication issues:

1. Run a Mail-Tester Diagnostics: Go to mail-tester.com, copy the unique test email address, and send a message from your business domain to that address. Read the report score.
2. Consolidate SPF: Ensure your domain has only one SPF record. If you use Google and Mailchimp, combine them into one TXT record:

   v=spf1 include:_spf.google.com include:servers.mcsv.net ~all

3. Activate DKIM: Go to your email console (e.g., Google Workspace Admin Console > Apps > Google Workspace > Gmail > Authenticate email), generate the DKIM record, and publish the TXT record to your DNS panel.
4. Publish DMARC: Publish a TXT record for _dmarc.yourdomain.com with the value:

   v=DMARC1; p=none; rua=mailto:dmarc-reports@yourdomain.com

5. Summary Checklist

To maintain high deliverability:

• Verify that you have exactly one SPF record containing all sending IPs.
• Enable DKIM signatures for all platforms (CRM, billing, marketing).
• Publish DMARC monitoring and gradually transition to quarantine.
• Monitor your spam complaint rates in Google Postmaster Tools.