Why MailCheck?

The only free, open-source email deliverability checker with SPF, DKIM, DMARC, MTA-STS, TLS-RPT, BIMI, batch mode, and a clean REST API. No signup required.

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Comparison

How MailCheck Stacks Up

Feature-by-feature comparison of email deliverability tools. MailCheck is the only tool that combines all checks with API access at zero cost.

Feature	📧 MailCheck	MXToolbox	DMARC Analyzer	Mail-Tester	dmarcsyndicator
SPF Check	✅	✅	✅	✅	❌
DKIM Check	✅	✅	✅	✅	❌
DMARC Check	✅	✅	✅	✅	✅
MTA-STS	✅	❌	❌	❌	❌
TLS-RPT	✅	❌	❌	❌	❌
BIMI	✅	❌	❌	❌	❌
REST API	✅	❌ (paid)	❌ (paid)	❌	❌
Batch Mode	✅	❌	✅	❌	✅
Scoring (0–100)	✅	❌	❌	✅ (10-point)	❌
CLI Tool	✅	❌	❌	❌	✅
Free Tier	✅ Unlimited	✅ Limited	❌	✅ 1/day	✅
No Signup Required	✅	❌	❌	✅	✅
Open Source	✅ MIT	❌	❌	❌	✅
Self-Hostable	✅	❌	❌	❌	✅
Price	Free	Freemium	$129/mo+	Free (limited)	Free

Get Started

Start Checking Domains in 30 Seconds

No signup, no API key, no credit card. Just a curl away.

# Check any domain instantly

curl https://korpo.pro/api/v1/check/gmail.com

# Install the CLI

pip install --index-url https://korpo.pro/git/api/packages/mailcheck/pypi/simple/ mailcheck

Try MailCheck Free →