Spam Score
Spam score is a numeric rating assigned to an email by spam filters that predicts how likely the message is to be classified as spam.
What Is Spam Score?
Spam filters evaluate dozens of factors to calculate a spam score: the subject line, email content, HTML quality, image-to-text ratio, authentication records, sender reputation, and the presence of known spam triggers. Tools like SpamAssassin assign point values to each factor, and if the total exceeds a threshold (typically 5.0), the email is flagged as spam. Modern spam filters also use machine learning that considers recipient behaviour — if many recipients mark similar emails as spam, future messages from that sender are more likely to be filtered.
Why It Matters for Newsletters
Even well-intentioned newsletters can trigger spam filters if they use certain phrases, have poor HTML, or lack proper authentication. Understanding spam scoring helps you craft emails that reliably reach the inbox. A high spam score affects not just individual emails but your overall sender reputation.
Best Practices
- Avoid spam trigger phrases like 'Act now', 'Free money', or excessive capitalisation
- Maintain a good text-to-image ratio — don't send image-only emails
- Include a plain text version alongside your HTML email
- Use a consistent From name and address
- Test your emails with spam scoring tools before sending
How Aldus Handles This
Aldus's AI generates newsletter content that's naturally optimised for deliverability. The platform avoids spam trigger patterns, maintains proper HTML structure, and always includes plain text alternatives — all of which keep your spam score low.