BounceLens is a free email list checker for teams that send email: marketers, online shops, sales teams and developers. Paste a list or upload a CSV and it finds the addresses that will hurt your sending: broken format, domains that don't exist or have no mail server, typos of big providers with the fix (gmial.com to gmail.com), disposable (throwaway) addresses from a list of nearly 9,000 domains, duplicates (including the same Gmail inbox written with dots or +tags), and shared inboxes like info@ and sales@. There is no signup, no credits and no daily limit. The check runs in your browser, so your list is never uploaded; only domain names are looked up through public DNS. Addresses that pass are marked "unconfirmed", not "verified", because BounceLens does not do a mailbox check. The same checks are available as a browser extension for Chrome, Edge and Firefox, a Google Sheets add-on, an Excel add-in, free plugins for WordPress, Craft CMS and Joomla, a free JSON API, a self-hosted Docker image, and an MCP server for AI assistants.
