Question 1

What does the spam checker test?

Accepted Answer

The spam checker analyzes your email across five dimensions: header correctness (Message-ID, date formatting, routing), content patterns (spam trigger words, formatting ratio, image-to-text balance), authentication records (SPF, DKIM, DMARC configuration), link reputation (URL scanning against malicious and phishing databases), and an overall weighted spam score. Each dimension contributes independently to the final score, so you can pinpoint exactly which factor is dragging deliverability down.

Question 2

How is the spam score calculated?

Accepted Answer

The score is a weighted composite of multiple factors: SpamAssassin-style rule matching for known spam patterns, content heuristics that evaluate text-to-HTML ratio and keyword density, authentication checks for SPF/DKIM/DMARC alignment, link reputation analysis across all URLs in the body, and header inspection for structural issues. Each factor produces a sub-score, and the final spam score is a normalized value from 0 (clean) to 10 (certain spam). Scores below 3 are considered safe for most ISPs.

Question 3

What is content classification?

Accepted Answer

Content classification uses LLM-powered analysis to categorize your email by intent: promotional, transactional, notification, newsletter, or automated reply. The classifier examines subject lines, body content, and structural patterns to determine what type of email you are sending. This matters because ISPs route different categories differently. A transactional email flagged as promotional may land in the Promotions tab instead of the primary inbox.

Question 4

Can I test emails before sending?

Accepted Answer

Yes. You can submit raw MIME content or plain HTML to the spam check endpoint for pre-send analysis. This lets you test subject lines, body content, and header configurations before any message reaches a real recipient. Many teams integrate this into their email template review workflow or CI/CD pipeline to catch spam triggers before deployment.

Question 5

How does link reputation checking work?

Accepted Answer

The spam checker extracts every URL from your email body and checks each one against known malicious and phishing databases. It also evaluates URL shorteners, redirect chains, and domain age. A single blacklisted link can cause an otherwise clean email to be flagged as spam by major ISPs. The checker reports each URL individually so you can identify and replace problematic links before sending.

Question 6

What authentication checks are included?

Accepted Answer

The spam checker verifies SPF record validity and alignment, DKIM signature presence and key strength, DMARC policy configuration and reporting setup, and checks for common misconfigurations like overly permissive SPF includes, missing DKIM selectors, or DMARC policies set to p=none without a path to enforcement. Each check returns a pass/fail status with specific remediation guidance.

Question 7

How accurate is the spam score?

Accepted Answer

The spam score is calibrated against filtering behavior observed at Gmail, Outlook, Yahoo, and other major ISPs. Scores are regularly validated against real delivery outcomes across millions of messages. While no score can guarantee inbox placement (ISPs use proprietary signals including recipient engagement history), MailOdds scores correlate strongly with actual filtering decisions and provide a reliable pre-send signal.

Question 8

Is there an API for automated spam testing?

Accepted Answer

Yes. The POST /v1/spam-checks endpoint accepts raw email content and returns a full spam analysis within seconds. This is designed for CI/CD integration, where you can automatically test every email template change before it reaches production. The endpoint supports both raw MIME and HTML input, and returns structured JSON with individual check results, sub-scores, and the overall spam score.

Email Spam Checker

Five Checks. One Endpoint.

Spam Score Analysis

Header Analysis

LLM Content Classification

Link Reputation

Authentication Verification

One Request. Full Analysis.

Part of the MailOdds Platform

Email Sending API

DMARC Monitoring

Deliverability Platform

Frequently Asked Questions