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Start with a health check

EmailToolBox - Free Email Checker & DNS Lookup Tools

Enter a domain to check its email configuration, authentication and reputation.

Check your email domain, DNS, SPF, DKIM, DMARC, MX records and blacklist status.

MXSPFDKIMDMARCBlacklistSMTPPTRMTA-STSBIMI

Get an Email Health Score with clear guidance on what to fix.

Free
No signup
Instant results
65
Tools Available
44
DNSBL Sources Checked
237
Email Guides

Popular Email Tools

Start with the tools most people need to diagnose email problems.

Email Health Check
Get an overall health score for your domain's email setup.
Email Deliverability
Analyze authentication, reputation and DNS for better inbox placement.
Email Blacklist Checker
Check if your domain or IP is listed on major blacklists.
Email Header Analyzer
Paste email headers to trace the delivery path and authentication results.
SPF Checker
Check and validate your domain's SPF record.
DKIM Checker
Verify DKIM signatures for your domain.
DMARC Checker
Check and analyze your domain's DMARC record.
MX Lookup
Look up mail exchange records for a domain.

Email Authentication Tools

Validate and configure SPF, DKIM and DMARC to stop spoofing and improve deliverability.

SPF Checker
Validate SPF records to prevent email spoofing.
DKIM Checker
Verify DKIM signatures and email authentication.
DMARC Checker
Check and analyze DMARC records and policies.
SPF Generator
Generate an SPF record for your domain.
DMARC Generator
Build a DMARC record with the right policy.
DMARC Report Analyzer
Parse DMARC aggregate reports to see who sends as your domain.
BIMI Checker
Check Brand Indicators for Message Identification.
MTA-STS Checker
Check MTA Strict Transport Security policies.

Email Deliverability Tools

Find out why emails go to spam and improve inbox placement.

Email Deliverability
Comprehensive deliverability and inbox placement analysis.
Email Verifier
Verify email addresses, formats and deliverability.
IP Blacklist Checker
Check if your IP address is listed on DNSBLs.
Domain Blacklist Checker
Check if your domain is listed on blacklists.
Email Header Analyzer
Analyze headers to find delivery problems.
SMTP Test
Test SMTP server connectivity and authentication.

DNS & Email Infrastructure

Look up the DNS records that control where and how your email is delivered.

MX Lookup
Check mail exchange records for a domain.
DNS Lookup
Query all common DNS record types.
DNS Propagation
Check DNS propagation across global nameservers.
PTR/rDNS Record Lookup
Reverse DNS lookup for IP addresses.
SMTP Test
Test SMTP server connectivity and authentication.

Compliance & Validation

Ensure your email programs meet global regulations and basic address hygiene.

GDPR Checker
Review consent, data usage, and privacy controls.
CAN-SPAM
Check US commercial email compliance.
CASL
Check Canadian anti-spam compliance.

Email Guides

Learn how to fix deliverability problems, read email headers and secure your domain.

Why is my email going to spam?
Learn about common reasons why emails end up in spam folders and how to fix them
How to set up SPF records
Complete SPF record setup guide, including syntax explanation and best practices
How to fix DMARC failure issues
Analyze DMARC validation failures and step-by-step solutions
Email Header Analysis Guide
Use headers to debug SPF/DKIM/DMARC results.
Blacklist & Health Check Workflow
Check blacklist status and overall email health regularly.
How to Pass Gmail Spam Filter (2025)
Modern requirements to avoid Gmail spam with authentication and content best practices

Explore All Tools

Browse by category to find exactly the deliverability, DNS, reputation, or compliance tools you need.

Deliverability Diagnostics
Delivery tests, spam analysis, and end-to-end health reports.
DNS & Authentication
DNS lookups, SPF/DKIM/DMARC validation, and policy analysis.
IP/Domain Reputation
Blacklist checks, IP scoring, and domain trust signals.
Compliance & Validation
Regulatory checks, consent flows, and address validation.

Why EmailToolbox.io?

Built by email experts for email professionals

Comprehensive Testing

All-in-one platform for email deliverability, DNS, and security testing

Real-time Results

Get instant feedback with detailed analysis and actionable recommendations

Professional Grade

Enterprise-level tools trusted by email administrators worldwide

Easy Integration

REST API and webhooks for seamless integration into your workflow

Built for marketers, devs & IT teams

Designed for cross-functional collaboration across marketing, engineering, and operations.

Privacy-first, no data stored

Your inputs are used only for real-time checks and are not persisted.

Ready to Improve Your Email Deliverability?

Start testing your email infrastructure today with our comprehensive suite of tools

Frequently Asked Questions

Answers about EmailToolBox's free online email testing and deliverability tools.

What is EmailToolBox?

EmailToolBox is a free online suite of email testing and domain diagnostics tools. Without signing up or installing anything, you can test SMTP servers, verify email addresses, analyze email headers, and check DNS, SPF, DKIM, DMARC, MX and blacklist records for any domain.

Is EmailToolBox free and does it require signup?

Yes. Every tool is free to use online and requires no account or registration. Just enter a domain, server, email address, or pasted headers and get instant results in your browser.

How do I check why my emails go to spam?

Start with the email health check or email header analyzer. Paste the full raw headers to see SPF, DKIM and DMARC pass/fail plus the Received routing chain. Fix any failed authentication record or missing DNS entry, then re-test.

Which email tools are included?

SMTP test, email verifier, email header analyzer, SPF/DKIM/DMARC checkers and generators, MX, DNS and blacklist lookups, email health check, deliverability analysis, and 65 free online tools in total.

Can I check MX, SPF, DKIM and DMARC records for a domain?

Yes. Enter your domain in the home search box to run a full email health check that covers MX, SPF, DKIM, DMARC and blacklist status, with a health score and prioritized recommendations.

How do I check if my domain or IP is on a blacklist?

Enter the domain or IP in the blacklist checker. It queries 44 DNSBL sources in one run, including Spamhaus, Barracuda, UCEPROTECT and Abusix, and resolves the domain's MX records so the mail server IPs are tested as well. Each result links to the provider's official lookup page for delisting.