The only auditable email verifier
Verify emails.
Prove your results.
Every ZeroBounce, NeverBounce, or Kickbox result is a black box — you just trust the vendor. ZI² Verify signs every verification with an Ed25519 key, publishes the JWKS publicly, and gives your prospect a one-click way to prove the result was real. Same accuracy. Zero vendor lock-in.
No credit card · 100 verifications on us · instant setup, no sales call
Certified receipt
How it works
Verify. Sign. Prove.
Three steps turn a checkmark into evidence anyone can audit.
Step 01
Verify
Send one address or a list of 100,000. MX, SPF, DMARC, disposable + role detection, catch-all probing and anti-greylisting — the same engine that runs ZI² Suite Mail Validator in production since Q1 2026.
Step 02
Sign
Every result is signed with an Ed25519 key over the exact checks that ran, when, and against which MX. The signing keys are published openly — nothing to take on faith.
Step 03
Prove
Hand a prospect the receipt. They paste it into our public verifier and confirm it is real in one click — no account, no login, no vendor to trust. That is the wedge.
Everything in the box
A clean list, and the proof to back it.
Deliverability-grade accuracy
MX, SPF, DMARC, DNSSEC, MTA-STS, DANE, catch-all and role-account detection with graylist tolerance.
Signed at every check
Ed25519 signature over the canonical result. Public JWKS at /.well-known/zi2cert.jwks.
Batches to 100,000
Async list validation with reserved-then-settled credits, webhook on completion, CSV out.
Sub-second single checks
Synchronous /v1/validate returns a signed verdict, typically well under a second.
A real REST API
Bearer keys, scopes, idempotency keys, cursor-paginated history. OpenAPI spec included.
Drop-in integrations
Zapier, Make, and a ready-to-import Postman collection. Webhooks for batch events.
Yours, not ours
Self-hosted engine, keys you can audit, zero lock-in. Export a cleaned list any time.
Auditable history
Every validation is retained, scored and queryable — build your own dashboard against /v1/results.
The ZI² Certified difference
A verdict is an opinion.
A signed receipt is evidence.
Anyone can return “valid.” Only ZI² Verify hands your prospect a receipt they can check themselves — the Ed25519 signature is verified against keys published at verify.zi2.app/.well-known/zi2cert.jwks. Paste it into /verify-receipt and prove it in one click — no account required.
Same accuracy as the incumbents
MX / SPF / DMARC, disposable + role, catch-all, anti-greylisting.
Signed at every check
Ed25519 over the exact checks — the key id and signature travel with the result.
Verifiable by anyone
Your prospect confirms the result independently. That is the moat.
Fits your stack
Wire it up in minutes.
Start with 100 credits, free.
No card. Pay-as-you-go credit packs or monthly plans — your keys, your data, cancel anytime.
Questions
Good ones, answered.
How is this different from ZeroBounce, NeverBounce or Kickbox?
Their result is a black box — you trust the vendor. ZI² Verify signs every verification with an Ed25519 key and publishes the JWKS publicly, so your prospect can prove the result was real without trusting you or us. Same accuracy, zero lock-in.
What does a verification cost?
One credit per email. You start with 100 free credits — no card. After that, buy credit packs or a monthly plan; see pricing.
How accurate is the engine?
It is the ZI² Suite Mail Validator engine, in production since Q1 2026 — full MX/SPF/DMARC analysis, disposable and role detection, catch-all probing and anti-greylisting.
Can anyone really verify a receipt?
Yes. Paste any ZI² Certified receipt into the public verifier — it checks the Ed25519 signature against our published keys. No account required.
Do you have an API and docs?
Yes — a versioned REST API at /v1, a full API reference, an OpenAPI spec, a Postman collection, and Zapier/Make integrations.
Verify emails. Prove it.
Join on 100 free credits and send a receipt your prospect can audit today.