About uChecker
uChecker checks raw mailing lists and keeps the full SMTP reply. Upload a .txt or .csv, run up to 9 million addresses in one job at about 3200 a minute, no pre-clean. Results are Good, Bad and Risk. Unknown is never counted valid. Dashboard app.uchecker.net, API api.uchecker.net/docs, Telegram @uchecker_bot, MCP https://uchecker.net/mcp. Thirteen DNS tools stay free at https://uchecker.net/tools.
uChecker is an email verification service built for raw mailing lists, and it keeps the full SMTP reply for every address so you can audit each result. Upload a .txt or .csv file and run up to 9 million addresses in a single job at roughly 3200 addresses a minute, with no pre-clean step required. Every address lands in one of three buckets: Good, Bad or Risk, and an Unknown response is never counted as valid, so your deliverability numbers stay honest. Work from the dashboard at app.uchecker.net, automate through the API documented at api.uchecker.net/docs, check lists from Telegram with @uchecker_bot, or connect an AI agent through MCP at https://uchecker.net/mcp. Thirteen DNS and deliverability tools, including MX, SPF, DMARC and blacklist lookups, stay free at https://uchecker.net/tools.
