Why are my emails landing in the spam folder, and how can I improve deliverability?

If your emails are being marked as spam despite having correct technical settings like SPF and DKIM, the issue often lies within the email's content and formatting. Spam filters use sophisticated algorithms to analyze content for patterns commonly used in phishing and spam campaigns.

Here are several common content-related issues that can negatively impact your email deliverability and how to fix them:

• Inconsistent Domains in Links

  • Problem: Your email contains links to multiple different root domains (e.g., your logo links to yourbrand.com while the main call-to-action button links to another-domain.net). This is a major red flag for spam filters as it mimics a classic phishing technique where a legitimate brand is used to mask a malicious link.
  • Solution: Ensure all links within a single email point to your primary domain or its legitimate subdomains (e.g., yourbrand.com, promo.yourbrand.com, news.yourbrand.com). Consistency is key to building trust with email providers.

• Hidden Content or Symbols

  • Problem: The email's HTML code contains text or elements hidden with CSS (e.g., display: none;) or invisible characters. Spammers historically used these techniques to hide keywords and trick filters, so now their presence is highly suspicious.
  • Solution: Remove any hidden elements from your email template. All content present in the code should be visible to the end-user.

• "Spammy" Keywords and Phrases

  • Problem: Using aggressive marketing language, especially phrases that promise financial gains (e.g., "up to 20% annual return", "easy money"), can trigger spam filters.
  • Solution: Opt for more neutral and value-focused language. Instead of making specific financial promises, describe the potential or features of your product. Let the user click through to a landing page for more detailed information.

• Missing Plain-Text Version

  • Problem: Your email is sent only in HTML format without a plain-text alternative. Legitimate senders almost always provide a plain-text version for email clients that cannot render HTML.
  • Solution: Ensure your emails are sent as multipart messages, including both text/html and text/plain versions. The plain-text version does not need complex formatting but should contain the core message and links.

• Improperly Formatted Preheader

  • Problem: The preheader (the preview text shown after the subject line in an inbox) is filled with invisible characters or a long string of non-breaking spaces ( ) to create empty space.
  • Solution: Use the preheader for its intended purpose: to provide a short, engaging summary of the email's content. This improves user experience and appears more legitimate to filters.

Before launching a large campaign, it is highly recommended to test your email template using third-party services like Mail-tester.com or SpamAssassin to check its spam score and identify potential issues.