Free Tools
Email deliverability
toolbox
Free tools to check, test, and fix your email deliverability. No account required. Powered by the same engine that runs Stekpad.
Authentication
SPF Record Checker
Validate your SPF record, check DNS lookup count, detect misconfigurations, and get fix recommendations.
Authentication
DKIM Record Checker
Look up DKIM records across 18 common selectors, validate key strength, and verify your signing configuration.
Authentication
DMARC Record Checker
Check your DMARC policy, verify reporting addresses, analyze subdomain policy, and get upgrade recommendations.
Reputation
Blacklist Checker
Check any IP address or domain against 12 major DNS blacklists including Spamhaus, SpamCop, and Barracuda.
Infrastructure
DNS Lookup
Full DNS record lookup: MX, A, AAAA, NS, TXT, SOA records. See your complete email infrastructure at a glance.
Analysis
Email Header Analyzer
Paste raw email headers and get a visual breakdown: hop routing, delays, authentication results, and anomaly detection.
Verification
Email Verifier
Verify any email address: syntax validation, MX records, disposable detection, role address check, and domain typo correction.
Content
Spam Word Checker
Paste your email content and detect 300+ spam trigger words. Get a content grade (A-F) with severity breakdown and fix suggestions.
Content
Subject Line Tester
Score your email subject line for length, spam triggers, mobile truncation, personalization, and engagement signals. Real-time analysis.
Generator
SPF Record Generator
Select your email providers, add custom IPs, choose your policy, and generate a correct SPF record ready to paste into your DNS.
Generator
DMARC Record Generator
Configure your DMARC policy, reporting addresses, alignment mode, and generate a complete record with a step-by-step wizard.
Generator
Email Signature Generator
Create professional email signatures with 3 templates (minimal, classic, modern). Customize colors, add social links, copy HTML for Gmail or Outlook.
Compliance
Email Compliance Checker
Check CAN-SPAM (US), GDPR (EU), and CASL (Canada) compliance with a 14-point interactive checklist. Identify legal risks before they become fines.
Infrastructure
Reverse DNS (PTR) Lookup
Check PTR records for any IP. Verify Forward-Confirmed reverse DNS (FCrDNS) — required by most mail servers to accept your email.
Audit
Domain Health Report
Complete deliverability audit: SPF, DKIM, DMARC, BIMI, MX, blacklists, and reverse DNS — all in one report with a single score.
Security
MTA-STS & TLS-RPT Checker
Check MTA-STS policy and TLS reporting. Verify TLS enforcement, policy file, max age, and MX patterns to prevent email interception.
Calculator
Warm-up ROI Calculator
Calculate how much revenue you lose from poor deliverability. See the business impact and ROI of warming up your domain.
Authentication
BIMI Record Checker
Check if your domain has BIMI configured. Verify logo URL, VMC certificate, and DMARC enforcement to display your brand in inboxes.
Calculator
Warm-up Calculator
Calculate how long it takes to warm up your domain. Get a personalized week-by-week ramp-up schedule based on your setup.
Calculator
Deliverability Score
Input your email metrics (bounce rate, open rate, spam complaints) and get a weighted 0-100 deliverability health score.
Why these tools are free
Good email deliverability starts with correct authentication and clean infrastructure. These tools help you diagnose problems before they affect your sender reputation. They are powered by the same DNS engine that Stekpad uses to monitor mailboxes — we just made it available to everyone, no strings attached.