Test and Improve Your Email Deliverability

Spam Cipher

See exactly where your emails land and why. Seed testing, content analysis, authentication monitoring, and AI classification in one platform.

Free Spam Check

or run a complete inbox placement test

Trusted by Clients Worldwide

Customer Reviews

"Inbox rate went from 62% to 94% after SpamCipher pinpointed the exact content triggers. We were blind before this tool."

Marcus Rivera

Head of Email, TechCorp

"Found a misconfigured DKIM key that had been silently failing for weeks. The DMARC validation alone saved us from a major crisis."

Sarah Kim

Email Marketing Manager, MailFlow

"We run 200+ campaigns a month. SpamCipher replaced three separate tools in our stack. The seed testing is a game changer."

James Park

Founder, SendPro Agency

"The AI classifier caught spam triggers our team completely missed. Our open rates jumped 28% in the first month after implementing SpamCipher's recommendations."

Elena Torres

VP of Growth, DataSync

Why Choose SpamCipher for Email Deliverability?

Inbox Insight

Powerful Spam Testing Tool

Test Your Email Deliverability:

Send a test email to our seed addresses and see real-time placement across Gmail, Outlook, Yahoo, iCloud, and 15+ providers. No guessing, no assumptions.

Real-time inbox vs. spam placement

15+ email providers monitored

Historical trend tracking

Try Inbox Test

Inbox Placement Testing - SPF, DKIM, DMARC validation and score dashboard

Content Analysis

60+ Rules Scan Every Element

Spam Testing:

Subject lines, body text, links, image-to-text ratio, and HTML structure are all checked against the same rules that spam filters use. Get a pass/warn/fail for each.

Subject line spam word detection

HTML structure validation

Image-to-text ratio checker

Analyze Content

Content Analysis - 60+ spam rules, HTML validation, and link checking

Authentication

Authentication Checker

Automatic Tests & Alerts:

Validates your email authentication stack and flags missing records, weak keys, alignment issues, and misconfigurations before they hurt your sender reputation.

SPF, DKIM, DMARC alignment

Weak key detection (1024-bit warnings)

DNS record configuration check

Check Auth

Authentication Checker - SPF, DKIM, DMARC validation and alignment

AI Classifier

AI Spam Classifier

Content Analysis:

Our model is trained on millions of spam/ham decisions across major providers. It predicts where your email will land with 98% accuracy, before you send to a single real subscriber.

98% prediction accuracy

Provider-specific models

Confidence scoring per prediction

Try AI Analysis

AI Spam Classifier - 98% accuracy prediction with provider breakdown

Developers

API 2.0 Integration

Integrate deliverability testing directly into your CI/CD pipeline, ESP workflow, or SaaS product. RESTful API with comprehensive documentation and SDKs for Node.js, Python, and Go.

<200ms

Average response time

99.95%

Uptime SLA

10k+

Requests/min

Get API Access

Node.js

import { SpamCipher } from '@spamcipher/sdk'; const client = new SpamCipher({ apiKey: process.env.SPAMCIPHER_KEY }); // Analyze email content const result = await client.analyze({ html: emailHtml, subject: 'Your order ships today', from: '[email protected]' }); console.log(result.score); // 9.2 console.log(result.placement); // "inbox" console.log(result.rules); // [{...}]

Frequently Asked Questions

Inbox placement testing uses seed email accounts at major providers (Gmail, Outlook, Yahoo, etc.) to determine exactly where your email lands — primary inbox, promotions tab, spam folder, or not delivered at all. Unlike open-rate tracking, seed testing gives you ground truth about deliverability.

We evaluate your email against 60+ rules that mirror what real spam filters check: subject line keywords, image-to-text ratio, HTML structure, link reputation, unsubscribe headers, and more. Each rule returns pass, warning, or fail with specific guidance on how to fix issues.

No. SpamCipher works with any ESP or email sending infrastructure. You simply send a test email to our seed address from your existing setup, and we analyze the result. No DNS changes, no code integration, no SDK installation required to get started.

Our machine learning model is trained on millions of real spam/ham classification decisions from major email providers. It predicts where your email will land across Gmail, Outlook, Yahoo, and others with 98% accuracy — giving you a pre-send confidence score before you send to your actual subscriber list.

Yes. SpamCipher offers a free forever tier that includes 5 content scans per day, basic authentication checks, and access to our free tools (Spam Score Checker, Blacklist Checker, DMARC Generator, SPF Flattener). No credit card required to sign up.

SpamCipher combines four layers of analysis in one platform: seed-based inbox placement testing, 60+ rule content analysis, authentication validation (SPF/DKIM/DMARC), and AI-powered spam classification. Most competitors offer one or two of these. We also provide a developer-first API for CI/CD integration.