Fixing Email Deliverability: Overcoming Spam Filters

Identifying the problems

• Overly enthusiastic tone
• Problematic words like get, access, free, open-source, click, or password etc.
• Content scoring poorly on urgency, shadiness, and over-promise
• Common salutations like "Hey there!" and emoji

Our approach to optimization

We were forced to take a more professional and straightforward approach in our revised emails, ensuring the content was informative and not too instructional.

Here are the original and optimised versions. As you can see, the changes are minor but significant. We've added a paragraph to enhance credibility and provide contact information.

Tools and services used

To diagnose and resolve our email deliverability issues, we utilized several tools:

• Mailmeteor Spam Checker and double check on Folderly Spam Words Checker helped identify potential spam triggers in our email content.
• IPQualityScore Email Spam Test Checker provided a detailed analysis of our emails’ deliverability scores.
• Mailreach.co provided a test on real inboxes, insights and recommendations.

Key findings

Our main deliverability issues came from spam filters on free personal Google and Microsoft accounts (such as Hotmail and Outlook) and Yahoo. These platforms flagged our emails as spam. The mentioned services have helped to identify content issues such as overly enthusiastic tone, use of potentially spammy words and content that scores poorly on urgency, shadiness and over-promising.

What we have analysed and passed

• Technical stuff :

  • The email server's IP is not listed on significant blacklists.
  • The domain isn't listed on any blacklist.
  • SPF check
  • DKIM check
  • DMARC check
  • The mail server Reverse DNS is properly configured.
  • There are MX records on this domain.

• Content Analysis :

  • No obvious known spam or risky words were detected.
  • The email body doesn't contain any blacklisted domains.
  • Used 3 links, fewer links, the better.
  • The email doesn't contain any attachments.
  • The text-to-image ratio is 99.8% text and 0.2% image. That's great.
  • No tracking pixel. The less tracking, the better for your deliverability.
  • No insecure links in your email body.
  • No shortened or shadowed links in your email body.
  • No broken links in your email body.
  • The HTML code of your email is light and not too heavy. That's fine.

Next steps

To further improve our email deliverability, we plan to:

1. Build domain reputation — focus on sending consistent, high-quality emails to improve our domain reputation.
2. Whitelisting for transactional emails — work on getting our domain whitelisted as a trusted sender of transactional emails, which should help improve deliverability to Gmail, Outlook, Hotmail, and Yahoo users.

By taking these steps, we aim to resolve the deliverability issues and ensure these kinds of "cold" emails are received promptly.

For curious ones

Read more about Gmail deliverability best practices