Email Verification Online & Bulk Email List Validation
Verify and clean email lists up to 9 million addresses: SMTP validator, MX record check, mailbox existence, spam traps, catch-all, and disposable email detection. Cut your sending costs.
Verify Addresses
Email address verification and list cleaning — made simple
Bulk email list validation up to 2 GB (~9 million addresses) per job. Automated verification in a Telegram bot, download Good/Bad results in one archive.
Upload your list in .txt or .csv format. No pre-cleaning needed — we remove bad domains automatically, at no charge.
Wait for processing to finish, then view and download the Good and Bad address lists together in one archive.
All your data is saved in the bot conversation so you can come back to it whenever you need.
A crystal-clean list, ready to send
The service is fast, and the price per verification will surprise you:
Validation cost — 0.2 ₽ per email address.
Validation speed — ~3,200 addresses per minute.
Convenient — everything runs inside a Telegram bot.
uChecker
A massive email address database — a few statistical facts about the validator
Email addresses uploaded
1 444 486 294
Unique email addresses
193 095 406
Valid email addresses
79 817 916
Full mailboxes, spam traps, and non-existent addresses
113 277 490
Pay for access
Pick the plan that fits your volume. The more addresses, the lower the price per address.
Free — up to 30 addresses
Try the service at no cost
1 000 addresses
0,20 ₽ per address
200 ₽
5 000 addresses
0,20 ₽ per address
1 000 ₽
10 000 addresses
0,20 ₽ per address
2 000 ₽
25 000 addresses
0,15 ₽ per address
3 750 ₽
50 000 addresses
0,15 ₽ per address
7 500 ₽
100 000 addresses
0,15 ₽ per address
15 000 ₽
200 000 addresses
0,08 ₽ per address
16 000 ₽
500 000 addresses
0,05 ₽ per address
25 000 ₽
750 000 addresses
0,05 ₽ per address
37 500 ₽
1 000 000 addresses
0,05 ₽ per address
50 000 ₽
uChecker accepts payment via:
uChecker Blog
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Email Verification Online and Bulk Email List Validation
uChecker is an online service for verifying email addresses and cleaning mailing lists. Each job handles up to 9 million addresses and returns a ready-made archive with two files — valid inboxes and bad addresses. List cleaning removes non-existent addresses, typos in popular domains, spam traps, role-based addresses, disposable emails, and full mailboxes, so your campaigns reach only real subscribers.
Why check whether an email address exists before you send? Every major ESP — Unisender, Mailchimp, Sendsay, Brevo, SendPulse — tracks your bounce rate and throttles deliverability when your list has too many dead addresses. A high bounce rate damages your domain and IP reputation, pushes messages into spam, and drives unsubscribes. One pass through the email validator typically removes 15-40% of junk and restores your inbox placement rate.
How the uChecker email validator works
The service checks each address through a cascade of validations. First comes syntax validation: is the format valid, are there any forbidden characters? Next is DNS validation and MX record check: does the domain have a working mail infrastructure? Then comes SMTP verification: we open a connection to the mail server and ask whether the mailbox exists, without sending any message. For major providers the validator uses their own APIs — more accurate than a blind SMTP probe, and it won't trigger a sender account block.
What email list cleaning finds
- Non-existent mailboxes — hard bounces that will fail on every send and hurt your reputation.
- Spam traps (spam trap addresses) — decoy addresses that providers plant to catch spammers.
- Catch-all domains — domains that accept mail for any address; the mailbox may or may not be active.
- Role-based addresses — info@, support@, admin@: sending marketing to these violates GDPR and common sense.
- Disposable email — temporary addresses (temp mail) that users create to pass a confirmation step and then abandon.
- Typos in popular domains: gmal.com, yandx.ru, mial.ru — the service suggests the correct spelling.
Who needs email list validation
Email marketers before a campaign, B2B teams before cold outreach, and any product that collects email addresses at registration — anyone who cares about deliverability and sender reputation. Cleaning your list before importing it into a new ESP saves money: you stop paying to send to dead addresses, and a high percentage of valid subscribers gives your domain a strong warm-up from day one.
How much does email verification cost
The price starts at 0.20 ₽ per address on the 1,000-address plan and drops to 0.05 ₽ at 500,000 addresses or more. The first 30 addresses are free — enough to run a test sample from your own list and see the validator's accuracy for yourself. Registration is through the Telegram bot @uchecker_bot; no credit card required.
The difference between email validation and email verification
In practice the terms are used interchangeably. Technically, there are three distinct levels:
- Syntax validation — checking the address format against RFC 5321/5322 with a regex. Fast, but the weakest level of assurance.
- DNS and MX validation — confirming that the domain has a working mail server. MX record checks cut out dead domains.
- SMTP mailbox verification — connecting to the mail server and confirming the address exists without sending a message (HELO/EHLO + MAIL FROM + RCPT TO).
API integration for validation in your product
Beyond the Telegram bot, uChecker offers a REST email validation API for embedding checks in a registration form, CRM (Bitrix24, amoCRM, HubSpot), or ESP. Asynchronous processing of large lists is supported via webhook. Full developer guide in the uChecker API blog post.
Want to go deeper on email validation terms, deliverability, and authentication (SPF, DKIM, DMARC)? Browse our email marketing and validation glossary (100+ articles covering SMTP, SPF, DKIM, DMARC, BIMI, bounce codes, domain warm-up, and mail protocols) and the email marketing blog.