uChecker.net Reviews & Product Details

uChecker checks email lists in bulk. Upload a .txt or .csv with up to 9 million addresses in one job. Dead domains drop out automatically and are not billed. Speed is about 3200 addresses a minute. Results come back as Good, Bad and Risk, as an archive or as JSON. The mail server's full response is stored for each address, so a deleted mailbox, a frozen account and a mailbox over quota stay different answers. Addresses that cannot be checked go to Unknown and are never counted as valid. Use the dashboard at app.uchecker.net, the REST API at api.uchecker.net/docs, or the Telegram bot. There is an MCP endpoint for agents. 100 free validations to try. 13 free email DNS tools with no account at https://uchecker.net/tools.