Free Email Tools - Verifier, Bounce Calc & More | BounceZero
All Free - No Signup Required

Free Email Tools

Everything you need to verify email addresses, calculate bounce rates, and embed verification on your own website - all free.

Free Tool - No Signup

Single Email Verifier

Check any email address instantly. Our 5-stage pipeline verifies syntax, MX records, SMTP delivery, catch-all status, and disposable detection - no account needed.

  • Syntax & RFC compliance check
  • DNS MX record lookup
  • SMTP mailbox verification
  • Catch-all domain detection
  • Disposable email detection
Full verifier page

Single Email Verifier

Bounce Rate Calculator

Enter values above to calculate
Free Calculator

Bounce Rate Calculator

Quickly calculate your email bounce rate and understand whether it's within acceptable industry thresholds.

Excellent < 0.5%
Acceptable 0.5% - 2%
At Risk 2% - 5%
Danger Zone > 5%
How to reduce your bounce rate
Embed Widget - Free to Use

Embed Email Checker on Your Website

Add a BounceZero email checker to any web page with a single iframe. Free for all websites - no API key required. Perfect for landing pages, contact pages, and demo integrations.

embed-snippet.html

<iframe src="https://bouncezero.io/embed/email-checker/" width="100%" height="120" frameborder="0" style="border-radius:12px"></iframe>
Preview widget

Widget Preview

↑ This is the embedded widget

More Verification Tools

Free Email Verifier

Verify any single address instantly. No signup.

Bulk Email Validation

Upload a CSV and clean your entire list.

SMTP Email Checker

Real mailbox verification at the server level.

Email Validation API

Integrate verification into your app or workflow.

Specialized Detection Tools

Disposable Email Checker

Detect throwaway and burner email addresses from 800+ providers.

Catch-All Email Checker

3-probe SMTP fingerprinting to identify catch-all domains.

Deliverability Test

Check SPF, DKIM, DMARC, blacklist status, and domain reputation.

Spam Trap Checker

Detect pristine, recycled, and typo spam traps in your list.

SPF Record Checker

Validate SPF, count DNS lookups against the 10-limit, flag common errors.

DMARC Record Checker

Validate policy, alignment, and rua reporting. Detect missing or duplicate records.

DKIM Record Checker

Auto-discover 24 common selectors. Validate keys, flag weak 1024-bit, detect revocation.

Email Header Analyzer

Decode the Received chain, SPF/DKIM/DMARC, hop delays, and sender IP. Private - not logged.

IP Blacklist Checker

Check any IP against 16 major DNSBLs in one request - Spamhaus, Barracuda, SpamCop, SORBS, more.

MX Lookup

Resolve MX records on any domain. See priorities, IPs, PTR, and auto-detect the mail provider.

Spam Score Checker

Paste subject + body. Get a SpamAssassin-style 0-10 score with rule-by-rule breakdown. Content never logged.

SPF Record Generator

Build a valid SPF record for 25+ ESPs (Google, M365, SendGrid, Mailgun, SES, Mailchimp...). Counts the 10-lookup limit.

DMARC Record Generator

Build a DMARC TXT record with policy + rua + alignment + rollout guidance. Pairs with the DMARC checker.