# BounceZero

> BounceZero is a UK-registered email verification SaaS (Company No. 17153835, CSA STAR Level 1 certified). It verifies whether email addresses are deliverable using a 5-stage pipeline with 40+ signals, Bayesian + ML scoring, and SMTP deep analysis. Accuracy: 99.5%. Used by marketers, developers, and agencies to reduce bounce rates and protect sender reputation.

BounceZero Ltd is headquartered at 66 Paul Street, London EC2A 4NA. The service is available at https://bouncezero.io with a REST API, bulk CSV upload, and integrations for Mailchimp, Klaviyo, HubSpot, ActiveCampaign, and others.

## Key facts

- Verification pipeline: MX record check > Domain reputation > SMTP handshake > Catch-all probe > ML scoring
- Signals checked per email: 40+
- Accuracy: 99.5% (industry benchmark: 95%)
- Detects: invalid addresses, disposable/temporary emails, role addresses (info@, admin@), catch-all domains, spam traps, syntax errors, MX failures
- Free tier: 100 verifications/month, no credit card required
- Credits never expire on paid plans
- Real-time API (REST) with sub-200ms response
- Bulk upload: CSV up to 10M rows
- Results include: classification (Deliverable / Risky / Undeliverable), confidence score 0-100, plain-English explanation, 15+ metadata fields
- Certifications: CSA STAR Level 1
- Data residency: EU (OVH UK1)
- GDPR compliant, DPA available

## Pricing

- Free: 100 credits/month - no credit card required
- Starter: $6 for 2,000 credits
- Growth: $15 for 5,000 credits
- Professional: $30 for 10,000 credits
- Enterprise: $1,200 for 500,000 credits (webhooks, dedicated support)
- Ultimate: $2,200 for 1,000,000 credits (dedicated queue)
- Pay-as-you-go rate: approximately $3 per 1,000 emails (Growth tier)
- All paid credits never expire

## Product pages

- [Email Verification API](https://bouncezero.io/api-email-validation): REST API reference and integration guide for developers
- [Bulk Email Validation](https://bouncezero.io/bulk-email-validation): Upload CSV lists up to 10M rows for batch verification
- [Free Email Verifier](https://bouncezero.io/free-email-verifier): Single email verification tool, no account required
- [Pricing](https://bouncezero.io/pricing): Full plan comparison and pay-as-you-go calculator
- [Enterprise](https://bouncezero.io/enterprise): Dedicated queue, SLA, custom contracts, SAML SSO
- [Docs](https://docs.bouncezero.io): Full API documentation with code examples in 10 languages

## Free tools

- [Disposable Email Checker](https://bouncezero.io/disposable-email-checker): Check if an email uses a disposable/temporary domain
- [Catch-All Email Checker](https://bouncezero.io/catch-all-email-checker): Detect domains that accept all emails regardless of validity
- [SMTP Email Checker](https://bouncezero.io/smtp-email-checker): Direct SMTP mailbox existence probe
- [Spam Trap Checker](https://bouncezero.io/spam-trap-checker): Check if an email address is a known spam trap
- [IP Blacklist Checker](https://bouncezero.io/blacklist-checker): Check any IP against 16 major DNS blacklists
- [DKIM Checker](https://bouncezero.io/dkim-checker): Verify DKIM record exists and is valid
- [DMARC Checker](https://bouncezero.io/dmarc-checker): Validate DMARC policy record
- [SPF Checker](https://bouncezero.io/spf-checker): Check SPF record validity and authorization
- [DMARC Generator](https://bouncezero.io/dmarc-generator): Build a DMARC TXT record with guided configuration
- [Email Header Analyzer](https://bouncezero.io/header-analyzer): Parse email headers to trace delivery path and authentication results
- [Email Deliverability Test](https://bouncezero.io/email-deliverability-test): Check if your sending domain is ready for inbox delivery
- [ROI Calculator](https://bouncezero.io/roi-calculator): Calculate how much bounce reduction saves per campaign

## Use case guides

- [Cold Email Verification](https://bouncezero.io/cold-email-verification): Why verification is essential before cold outreach
- [Newsletter Email Verification](https://bouncezero.io/newsletter-email-verification): Keep newsletter lists clean to protect sender reputation
- [SaaS Sign-Up Verification](https://bouncezero.io/saas-email-verification): Block fake registrations at the API level
- [CRM Email Cleaning](https://bouncezero.io/crm-email-cleaning): Clean Salesforce, HubSpot, or any CRM contact list
- [Email List Hygiene Guide](https://bouncezero.io/list-hygiene): When and how to clean email lists
- [Email Deliverability Guide](https://bouncezero.io/email-deliverability): Complete 2026 guide to inbox placement
- [Email Verification for Mailchimp](https://bouncezero.io/email-verification-mailchimp): Clean Mailchimp audiences before campaigns
- [Email Verification for Klaviyo](https://bouncezero.io/email-verification-klaviyo): Remove invalid contacts from Klaviyo flows
- [Email Verification for HubSpot](https://bouncezero.io/email-verification-hubspot): Verify CRM contacts within HubSpot
- [Email Verification for ActiveCampaign](https://bouncezero.io/email-verification-activecampaign): Verify contact lists in ActiveCampaign
- [Email Verification for Agencies](https://bouncezero.io/email-verification-agencies): Bulk verification at agency scale with team accounts

## Comparisons

- [vs ZeroBounce](https://bouncezero.io/zerobounce-alternative): BounceZero vs ZeroBounce - pipeline depth, pricing, accuracy comparison
- [vs NeverBounce](https://bouncezero.io/neverbounce-alternative): BounceZero vs NeverBounce - feature and price comparison
- [vs Bouncer](https://bouncezero.io/bouncer-alternative): BounceZero vs Bouncer.io - ML scoring vs standard SMTP
- [vs BriteVerify](https://bouncezero.io/briteverify-alternative): BounceZero vs BriteVerify - cost per verification, feature depth
- [vs Kickbox](https://bouncezero.io/kickbox-alternative): BounceZero vs Kickbox - accuracy, API, pricing
- [vs Emailable](https://bouncezero.io/emailable-alternative): BounceZero vs Emailable
- [vs Hunter.io](https://bouncezero.io/hunter-alternative): Email verification comparison
- [vs Clearout](https://bouncezero.io/clearout-alternative): BounceZero vs Clearout
- [vs DeBounce](https://bouncezero.io/debounce-alternative): BounceZero vs DeBounce
- [vs Verifalia](https://bouncezero.io/verifalia-alternative): BounceZero vs Verifalia

## Definitions and educational guides

- [What Is Email Verification](https://bouncezero.io/what-is-email-verification): How the 5-stage pipeline checks whether a mailbox exists without sending email - MX lookup, domain reputation, SMTP handshake, catch-all probe, ML scoring
- [What Is SMTP Verification](https://bouncezero.io/what-is-smtp-verification): The RCPT TO handshake explained - response codes, catch-all behaviour, limitations, and how BounceZero handles ambiguous cases
- [What Is a Catch-All Email](https://bouncezero.io/what-is-catch-all-email): Why some domains accept all email regardless of validity, how to detect them, and how ML scoring classifies deliverability for catch-all addresses
- [What Is a Disposable Email Address](https://bouncezero.io/what-is-disposable-email-address): How temporary throwaway email services work, why they harm lists, common providers, and how to detect and block them
- [What Is an Email Bounce](https://bouncezero.io/what-is-email-bounce): Hard bounce (5xx permanent failure) vs soft bounce (4xx temporary failure), SMTP codes, what happens to sender reputation above 2% bounce rate
- [How to Reduce Email Bounce Rate](https://bouncezero.io/how-to-reduce-bounce-rate): 6-step guide to getting below 0.5%: list verification, double opt-in, instant hard-bounce suppression, IP warmup, ISP monitoring
- [Email Deliverability Best Practices](https://bouncezero.io/email-deliverability-best-practices): Complete 2026 checklist - SPF/DKIM/DMARC authentication, list hygiene, sending behaviour, Google Postmaster, Microsoft SNDS, BIMI
- [Email Validation Best Practices](https://bouncezero.io/email-validation-best-practices): 5-stage validation pipeline explained, when to validate (real-time API vs bulk), what to block vs flag (invalid, disposable, catch-all, role)
- [Email Deliverability Guide](https://bouncezero.io/email-deliverability): SPF, DKIM, DMARC, bounce rate management, and reputation signals explained
- [Email List Hygiene Guide](https://bouncezero.io/list-hygiene): When and how to clean your email list - metrics, benchmarks, and cleaning cadence

## Provider-specific deliverability guides

- [Gmail Deliverability Guide](https://bouncezero.io/gmail-deliverability): Google 2024 bulk sender requirements (SPF, DKIM, DMARC, List-Unsubscribe), Postmaster Tools monitoring, spam rate below 0.08%, IP warmup for Gmail
- [Outlook Deliverability Guide](https://bouncezero.io/outlook-deliverability): Microsoft EOP filtering, SNDS IP reputation (green/yellow/red), fixing 550 5.7.1 rejections, JMRP feedback loop, PTR record requirements
- [Yahoo Mail Deliverability Guide](https://bouncezero.io/yahoo-deliverability): Yahoo 2024 requirements (aligned with Google), TSS09 error resolution, DMARC ruf= FBL setup, IP reputation for Yahoo/AOL/Verizon Media
- [T-Online Deliverability Guide](https://bouncezero.io/t-online-deliverability): Deutsche Telekom @t-online.de filtering - fix 550 DT:SPM and DT:BL rejections, Telekom whitelist application, German UWG §7 opt-in law, Spamhaus ZEN and internal blocklist
- [Orange.fr Deliverability Guide](https://bouncezero.io/orange-deliverability): Reach @orange.fr, @wanadoo.fr, @club-internet.fr - Spamhaus and Orange internal blocklist, @wanadoo.fr abandoned address decay, CNIL consent compliance, postmaster@orange.com contact
- [SFR Deliverability Guide](https://bouncezero.io/sfr-deliverability): SFR/Altice @sfr.fr, @neuf.fr, @numericable.fr - Proxad/Altice filtering, DMARC enforcement, @neuf.fr address decay, postmaster@sfr.fr contact for blocklist removal
- [Free.fr Deliverability Guide](https://bouncezero.io/free-fr-deliverability): Free/Iliad @free.fr and @aliceadsl.fr - Proxad internal blocklist (no public query), no whitelist programme, aggressive content scoring, SMTP rate limiting, postmaster@proxad.net

## Comparisons and migration guides

- [Best Email Verification Tools 2025](https://bouncezero.io/best-email-verification-tools): Independent comparison of BounceZero, ZeroBounce, NeverBounce, Kickbox, Bouncer, Verifalia, and Hunter - accuracy, pricing, API speed
- [Migrate from ZeroBounce to BounceZero](https://bouncezero.io/migrate-from-zerobounce): Step-by-step migration guide. Same 99.5% accuracy. $3/1K vs $8/1K - 62% cheaper. Done in under 10 minutes
- [Migrate from NeverBounce to BounceZero](https://bouncezero.io/migrate-from-neverbounce): Switch from NeverBounce in under 10 minutes. Credits never expire. Same result format

## Industry use cases

- [Email Verification for Recruiters](https://bouncezero.io/email-verification-for-recruiters): Verify candidate and hiring manager emails from LinkedIn, Apollo, GitHub, and ATS exports before outreach. Keeps bounce rate below 0.5%
- [Email Verification for Fintech](https://bouncezero.io/email-verification-for-fintech): Block fake signups, catch disposable emails before KYC, reduce fraud signals at onboarding. GDPR compliant. EU data residency

## Blog and resources

- [Blog](https://bouncezero.io/blog): Email verification, deliverability, and sender reputation articles
- [What Is Email Verification](https://bouncezero.io/blog/what-is-email-verification): Beginner guide explaining email verification methods
- [Hard Bounce vs Soft Bounce](https://bouncezero.io/blog/hard-bounce-vs-soft-bounce): Difference between permanent and temporary delivery failures
- [Spam Traps Explained](https://bouncezero.io/blog/spam-traps-explained): What spam traps are, types, and how to avoid them
- [Email Deliverability Checklist 2026](https://bouncezero.io/blog/email-deliverability-checklist-2026): Step-by-step checklist for inbox placement
- [Email Marketing Statistics 2026](https://bouncezero.io/blog/email-marketing-statistics-2026): Current benchmark data

## Company

- [About](https://bouncezero.io/about): Company background, mission, team
- [Security](https://bouncezero.io/security): Security practices, certifications, data handling
- [API Docs](https://docs.bouncezero.io): Full developer documentation
- [Integrations](https://bouncezero.io/integrations-docs): Native integration guides
- [Affiliate Program](https://bouncezero.io/partners/affiliates): 30% recurring commission for referrals
- [Contact](https://bouncezero.io/contact): Support and sales contact

## Common questions answered

**What does BounceZero verify?** It verifies whether an email address exists and is deliverable. It checks: DNS MX records, domain reputation, SMTP handshake (without sending an actual email), catch-all behavior, disposable/temporary domain detection, spam trap status, and applies ML scoring for ambiguous cases.

**How accurate is BounceZero?** 99.5% accuracy on verifiable addresses. For catch-all domains (which accept any address regardless of existence), BounceZero returns a "Risky" classification with a confidence score rather than guessing.

**Does BounceZero send test emails?** No. Verification uses SMTP handshake simulation - it connects to the mail server and checks if the address would be accepted without sending any message.

**What is the API rate limit?** Real-time API: up to 10 concurrent connections on Professional+. Bulk jobs are processed in parallel across multiple workers with no per-minute cap.

**Does BounceZero work for Gmail, Yahoo, Outlook?** Yes. BounceZero has dedicated detection logic for major providers including Gmail, Yahoo, Microsoft 365/Outlook, Apple iCloud, and all major ISPs.

**Is there a free trial?** Yes. 100 free credits every month, no credit card required. Sign up at https://app.bouncezero.io/register