About uChecker
uChecker checks large email lists and returns Good, Bad, Risk, and Unknown groups. Unknown addresses are not counted as valid. The full mailbox-server reply is kept, so you can see if an inbox was deleted, frozen, or full. Lists go in as txt or csv, up to 9 million addresses per job, about 3200 per minute. There is a web dashboard, a REST API, and a Telegram bot. Thirteen DNS tools stay free with no account: SPF, DKIM, DMARC, MX, BIMI, MTA-STS, TLS-RPT, plus generators and a domain health check. Cyprus.
What uChecker does
- Bulk email validation
- Checks lists up to 9 million addresses and groups results into Good, Bad, Risk, and Unknown.
- SMTP and DNS checks
- Uses syntax, DNS/MX, and SMTP validation without sending a test email.
- Detailed result reasons
- Keeps the mail-server response so users can see whether a mailbox is deleted, frozen, or full.
- Multiple access paths
- Provides a web dashboard, REST API, and Telegram bot.
- Free DNS toolkit
- Offers SPF, DKIM, DMARC, MX, BIMI, MTA-STS, TLS-RPT checks plus generators and domain health tools.
- Exportable results
- Downloads cleaned lists as an archive or exports JSON/CSV with reasons.
Who it’s for
Best suited to email marketers, B2B teams, and product teams that need to clean a list before sending. It also fits developers who want API access or teams maintaining sender reputation. Skip it if you need proof of subscriber consent or a tool that sends campaigns; uChecker validates technical deliverability signals, not permission to contact people.
What it costs
Free — up to 100 addresses. Paid validation starts at 0.20 ₽ per address for 1,000 addresses (200 ₽), drops to 0.15 ₽ at 25,000–100,000, 0.08 ₽ at 200,000, and 0.05 ₽ from 500,000 addresses. The website also lists 1,000,000 addresses at 50,000 ₽. No bank card is required for the first 100 addresses.