uChecker is unclaimed —

uChecker

Email validation and mailing list cleaning·uchecker.net

uChecker is an online service for verifying email addresses and cleaning mailing lists, processing up to 9 million addresses per job. It runs a cascade of checks — syntax, DNS/MX, and SMTP mailbox verification — to filter out non-existent mailboxes, full/frozen inboxes, blacklisted domains, disposable and role-based addresses. Results are split into three groups (Good, Bad, Unknown), with no charge for addresses that could not be resolved. It is accessible through a web dashboard, a REST API, and a Telegram bot.

What it's for

Cleaning a mailing list before a campaignVerifying a single email address in real time, e.g. at signupBulk validation of email lists via API with webhook notificationChecking domain email infrastructure (MX, SPF, DKIM, DMARC)Generating SPF, DKIM, DMARC, BIMI, MTA-STS and TLS-RPT recordsAnalyzing raw email headersTesting an SMTP server's handshake and configuration

Features 20

BIMI, MTA-STS and TLS-RPT record generators
Blacklist checking against DNSBL, Spamhaus and URIBL
Bulk email list validation of up to 9 million addresses per job
Detection of catch-all domains
Detection of disposable email addresses
Detection of role-based addresses (info@, support@)
DKIM checker and key generator
DMARC checker and generator
Email domain health check with a 0–100 setup score
Email header analyzer and SMTP server test
MX record and DNS validation
REST API for single real-time and bulk validation with webhook notification
Result export as archive, JSON, or CSV
Separate 'unknown/risk' classification for unresolvable addresses, not charged
SMTP verification of mailbox existence without sending an email
SPF checker and generator
Suppression list handling for invalid addresses
Syntax validation per RFC 5321/5322
Telegram bot for validation (@uchecker_bot)
Web dashboard with validation history and per-task analytics

At a glance

free tierAPI

TypeWeb app

DeploymentCloud

PlatformsWeb

LanguagesRussian, English

Foremail marketers, B2B teams doing cold email outreach, products with email signup forms

CompanyuChecker

Integrations

Bitrix24amoCRMHubSpotUnisenderMailchimpSendPulseBrevoSendsay

Resources

Docs

Pricing

All prices are stated in Russian rubles (₽) per address, sold as bulk packages from 1,000 to 1,000,000 addresses; no USD price is shown. API usage is billed in credits (1 credit = 1 address check) drawn from the same account balance. First 100 address checks are free. Payment is also accepted in cryptocurrency (USDT, Bitcoin, TON).

First 100 addressesFree

Meant to test validation accuracy on a sample before buying a package.

First 100 addresses checked free, no card required

1 000 addressesQuote

Bulk package of 1,000 address checks

5 000 addressesQuote

Bulk package of 5,000 address checks

10 000 addressesQuote

Bulk package of 10,000 address checks

25 000 addressesQuote

Bulk package of 25,000 address checks

50 000 addressesQuote

Bulk package of 50,000 address checks

100 000 addressesQuote

Bulk package of 100,000 address checks

200 000 addressesQuote

Marked as the best-value package on the pricing page.

Bulk package of 200,000 address checks

500 000 addressesQuote

Bulk package of 500,000 address checks

750 000 addressesQuote

Bulk package of 750,000 address checks

1 000 000 addressesQuote

Bulk package of 1,000,000 address checks

Per-address price drops from 0.20 ₽ to 0.05 ₽ as the purchased package size grows from 1,000 to 1,000,000 addresses.