How does stealth work?

Resenty communicates directly with mail servers using SMTP handshakes. We verify if a mailbox exists without ever sending the DATA command, making it invisible to the recipient.

How fast is bulk verification?

Large lists are checked in parallel and verdicts stream in live as they land — no queues, no overnight waits. Exact speed depends on how quickly the receiving mail servers respond.

No. Your credits stay active until they are used. We believe you should own what you pay for, with no monthly expiry traps.

Is it GDPR compliant?

Yes. We act as your data processor under a DPA, host in the EU, delete uploaded lists 90 days after a job completes, and encrypt data in transit and at rest. This site runs no third-party trackers or analytics.

A Catch-all server accepts all mail for a domain. Resenty detects this configuration and labels it as Risky so you can decide how to handle it.

How accurate is a verdict?

We resolve MX records, complete the SMTP handshake and cross-check every result against our catch-all, role-account and spam-trap data. On Hunter.io’s public benchmark of 929 B2B addresses, 85.6% of the verdicts Resenty committed to were correct — the benchmark section above covers method and limits.

Can I verify in bulk and through the API?

Both. Drop a CSV or TXT list of up to 100,000 rows in the dashboard, or send addresses through the API — same verdicts, one shared credit balance.

Resenty — Email verification that never sends an email

Will this email
ever bounce?

Watch demo

Deliverable {{ resultEmail }}

Sample check

This is what Resenty does.

A sample list, cleaned in front of you. The bad rows never make it to your next send.

Resenty / Bulk verify / Sample-list

Enterprise SMTP core

Validation with Absolute Precision.

Engineered for high-volume senders who require certainty before every send. Every address is checked at the mailbox over a live SMTP handshake — and nothing is ever delivered.

Live audit engine Sample data

SMTP_ENGINE_TRACE {{ d2Secured }}

analyzing connection… Handshaking

Rows checked

Emails sent

Launch dashboard

Live engine

250OK

The reply code read from the mail server. 250 means the mailbox exists; 550 means it doesn’t.

Stealth protection

RCPT probeActive

100% Invisible{{ d2Prog }}

Security standards

AES-256 at rest TLS 1.2+ in transit 90-day auto-delete

Product

Four features. Zero upkeep.

The parts of Resenty marketers use every day.

smtp · mx1.northloop.co

> RCPT TO:<maya.holt@northloop.co>

< 250 2.1.5 OK — mailbox exists

> QUIT // no DATA — nothing sent

deliverable · mailbox exists

subscribers_q3.csv

4,961 rows · sample file

Done

Deliverable4,388

Risky361

Invalid212

$ curl -X POST api.resenty.io/v1/validate-email

-d '{ "email": "maya@northloop.co" }'

{

"verdict": "deliverable",

"reason": "mailbox_exists"

}

Mailchimp synced 2m ago

HubSpot synced 14m ago

Signup webhook streaming

New signups verified in real time. Synced lists re-checked weekly — bounces never build back up.

Dashboard

See your list health in real time.

app.resenty.io/dashboard

Sample data

53% Deliverable

Validations · sample

84,292

Verified

44,675

Risky

6,128

Quick verify

name@domain.com

Verify now

API calls (24h)2,842

PlanPay as you go

Credit consumption

Auto-clean

Plug in. Never bounce again.

24/7

Your sources stream through Resenty and land back clean — automatically.

Clean

Integrations

Works with everything.

Connect Resenty to your entire marketing stack in seconds.

Explore 50+ more integrations

Developers

Building with Resenty?

Use our API for your own workflows — same verdicts, same engine, one shared quota.

View developer docs

POST /v1/validate-email

Case study results

The week one difference.

Same 4,961-contact list. We measured the campaign performance before and after Resenty verification.

Illustrative example

Phase 01 · Baseline

21.6%

Initial bounce rate

Phase 02 · Optimized

0.8%

Week one performance

Improvement factor27× Lower Bounce

21.6% (Legacy)0.8% (Resenty core)

Integrity audit

Every entry was verified via our Stealth SMTP Engine, isolating traps without shadow-pings.

Read the report

Compare

How Resenty compares.

32%Lower average price

NeverCredit expiry

100Free credits at start

Feature

RResenty

Provider A

Provider B

Price per 100K checks

$180

$210+

$265+

Free credits at signup

100

Credit expiry

Never

90 days

1 year

Public list prices, July 2026. Competitor names withheld.

See full pricing

Audited performance

85.6%

Total Accuracy

False positives

Accept-all

28%

Accuracy when the tool commits to an answer. Abstentions don't count for or against.

Methodology

Accuracy on committed verdicts

Lead Gen X* abstained on 58%96.4%*

RResenty85.6%

Competitor B66.8%

Competitor C65.5%

Read the full report

Pricing

Check only what you need.

Choose how many emails you want to check. No complicated plans.

Select quantity

Credits

Built for teams with a compliance checklist.

Your lists stay private. No address is ever emailed.

Request security documentation

SMTP handshakemaya.holt@northloop.co NOTHING SENT

EHLO250 OK MAIL FROM250 OK RCPT TO250 2.1.5 mailbox exists DATAnever sentstopped

No message ever sent

Resenty completes the SMTP handshake and stops before the message body. Nothing is ever delivered to the address being checked.

GDPR-ready processing

A data processing agreement is available on request.

Sole-operator access

No staff, contractors or third parties can read your lists. Production access is held by one person over key-based SSH with passwords disabled.

Encrypted end to end

TLS 1.2+ in transit, AES-256 at rest. Lists deleted after 90 days.

FAQ

Common questions.

Straight answers on accuracy, privacy, speed and credits.

Get started

Start with 100 free credits.

Verify your first hundred addresses in the next two minutes. Buy credits only when you like what you see.

Create free account Talk to sales

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No email is ever sent Credits never expire Live in under two minutes