Free Email Tools

Validate your email infrastructure with our free developer tools.

MBOX Viewer

Open .mbox mailbox exports in your browser, preview messages, inspect headers, review dates, and find attachment metadata without uploading email data.

EML Viewer

Open .eml files in your browser and inspect headers, MIME parts, attachments, and message body previews without uploading the email.

DNS Lookup Tool

Look up A, AAAA, MX, TXT, CNAME, NS, and CAA records for any domain with email-focused SPF, DMARC, and MX explanations.

Email Header Analyzer

Paste raw email headers to trace the delivery path, inspect SPF, DKIM, and DMARC results, and surface hop-by-hop delays.

Webhook Tester

Generate a temporary request bin, capture webhook payloads, inspect headers and JSON bodies, and copy replay commands.

SPF Record Checker

Validate your SPF record for syntax errors, DNS lookup limits, deprecated mechanisms, and best practices.

DKIM Checker

Look up DKIM selector records with DNS-over-HTTPS, parse the tags, validate key strength, and surface fixes for broken DKIM setups.

DKIM Record Generator

Create a copy-ready DKIM TXT record from a selector, sending domain, and public key, with DNS setup checks before you publish.

DMARC Record Generator

Generate DMARC DNS records for email authentication. Configure policy, reporting, and alignment options to get a ready-to-use TXT record.

DMARC Checker

Look up a domain's DMARC record, explain the policy, and flag reporting, pct, and subdomain enforcement gaps.

MX Record Lookup

Look up MX records for any domain to see which mail servers handle email delivery, their priorities, and TTL values.

Email Subject Line Tester

Analyze email subject lines for open rate optimization. Scores length, word choice, spam triggers, emoji usage, and personalization.

Email Signature Generator

Create a polished email signature with contact info, social links, brand colors, and copy-ready HTML for Gmail, Outlook, and Apple Mail.

Email Blacklist Checker

Check if your email server IP or domain is listed on major email blacklists (DNSBLs). Scan against Spamhaus, Barracuda, SORBS, and more.

SMTP Tester

Test an SMTP host, port, TLS mode, and optional credentials to verify mail server connection readiness before production sends.

Email Bounce Code Lookup

Look up SMTP bounce codes and full bounce messages with plain-English explanations, likely causes, and remediation steps.

Email List Deduplicator

Paste an email list and remove duplicates instantly. Normalizes case, whitespace, and Gmail aliases, with strict mode and CSV-friendly parsing.

Email Spam Score Checker

Test your email content for spam triggers, ALL CAPS, suspicious phrases, and risky formatting. Get a 0-100 spam score with specific fixes to improve inbox placement.

Email Deliverability Test

Check domain authentication, list health, reputation, and content readiness before sending a campaign. Get a 100-point inbox readiness score with fixes.

Email Warmup Plan Calculator

Generate a day-by-day email warmup schedule for new domains or IPs. Pick your target volume, ramp curve, and duration to get a copy-ready ramp plan.

Email Regex Validator

Test and validate email regex patterns against sample addresses. Live pass/fail results, with built-in Simple, Standard, HTML5, and RFC 5322 presets.

Automate email validation

MailParse validates SPF, DKIM, and DMARC on every inbound email.

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