Email List Checker

Privacy policy. Last updated 8 November 2026.

This browser extension checks a list of email addresses that you paste into it and shows which ones are likely to bounce. In short: the checking happens in your browser, only domain names are looked up, and nothing is sent to us.

What leaves your computer

When you press "Check", the extension looks up the domain part of each address (for example example.com from name@example.com) through Cloudflare's public DNS service at cloudflare-dns.com, to see whether that domain exists and can receive email. Full email addresses, names and the rest of your list are never sent anywhere. Cloudflare handles these lookups under its own public DNS privacy commitments.

What it does not do

• It does not contact mail servers or send any email.
• It does not collect, store, send or sell personal information or browsing history.
• It has no analytics, tracking, adverts or accounts, and no server of ours is involved.
• It does not read any web page you visit.

Permissions

• Access to cloudflare-dns.com: to look up domain names, only when you press "Check".

Storage

Nothing is stored. Your list and results disappear when you close the tab, unless you choose to download them as a CSV file or copy the valid addresses to your clipboard.

Contact

Questions: taz@aitaz.com. Made by Himanshu Bhatia (Taz).