Free Diagnostic Toolkit

Email Diagnostic Tools

Tools with guide so teams can diagnose issues quickly and take action with confidence.

Jump to any tool section to see what it checks and the fastest way to use it.

Authentication and Sender Health

Email Deliverability Scanner

Diagnose SPF, DKIM, DMARC, and BIMI readiness before deliverability issues impact campaigns.

What This Tool Helps You Do

  • Validate core sender authentication records in one pass.
  • Find missing, misaligned, or weak DNS values quickly.
  • Get practical next steps to improve inbox reliability.

How To Use It

  1. Open the tool and enter your primary sending domain.
  2. Run the scan and review SPF, DKIM, DMARC, and BIMI checks.
  3. Apply the recommended fixes in DNS and ESP settings.
  4. Re-scan to confirm critical checks are now passing.

Reputation Monitoring

IP and Domain Reputation Check

Check domain and IP reputation against major blacklist sources before poor trust affects inbox placement.

What This Tool Helps You Do

  • See whether your domain or sending IP appears on key reputation lists.
  • Identify risk signals that may impact inbox placement.
  • Prioritize remediation work before large-volume sends.

How To Use It

  1. Enter the sending domain or IP you want to evaluate.
  2. Run the lookup across the listed blacklist sources.
  3. Review hits, severity, and source-level details.
  4. Remediate flagged items, then re-check to verify status changes.

DNS Validation

DNS Record Scanner

Inspect live DNS responses by record type and resolver to troubleshoot authentication and infrastructure issues faster.

What This Tool Helps You Do

  • Check live DNS values across common record types.
  • Compare resolver responses to spot propagation mismatches.
  • Catch misconfigurations before they break send operations.

How To Use It

  1. Enter the domain or hostname to inspect.
  2. Select record type and resolver, then run the lookup.
  3. Review normalized DNS responses and validation notes.
  4. Correct records as needed and rerun checks for confirmation.

Transport Security

MTA-STS Checker

Validate MTA-STS DNS, policy file, certificate, and MX TLS support to strengthen secure mail transport.

What This Tool Helps You Do

  • Verify MTA-STS policy availability and syntax.
  • Confirm DNS signal and certificate alignment.
  • Surface TLS and MX issues that can weaken secure delivery.

How To Use It

  1. Enter your domain and run the MTA-STS validation.
  2. Review DNS, policy, certificate, and MX/TLS checks.
  3. Apply the recommended policy or DNS adjustments.
  4. Run the checker again to confirm enforcement readiness.

Header Diagnostics

Email Header Analyzer

Analyze raw email headers to review authentication outcomes, routing quality, compliance, and DNS-linked risks.

What This Tool Helps You Do

  • Decode complex headers into practical diagnostics.
  • Review SPF, DKIM, and DMARC outcomes with context.
  • Spot routing or policy issues that can affect trust and placement.

How To Use It

  1. Paste raw headers or upload a header file.
  2. Run analysis and review summary-level findings first.
  3. Inspect detailed sections for auth, routing, and compliance signals.
  4. Apply fixes and retest with a fresh message header sample.

Resource Center

More Resources for Your Team

Keep moving with deeper guides, FAQs, and definitions that help you turn diagnostics into better execution.

Need Expert Execution?

Turn Tool Findings Into Performance Gains

Share your scan results and goals. We will prioritize the highest-impact fixes, scope the right support model, and execute with your team.

  • Deliverability and authentication remediation
  • Lifecycle and campaign execution support
  • Platform setup, QA, and optimization