MailValidator — Email Validator & Verifier

MailValidator is a standalone Windows desktop application that cleans and verifies email lists at scale — from a handful of addresses up to roughly 10 million — before you send to them.

What it does: paste addresses directly into the app or attach .txt files, click Validate All, and get back one results table with a pass/fail column for every check: Fake (malformed or placeholder addresses), Horny-Pot (honeypot/spam-trap and adult-keyword addresses), Invalid MX (no working mail server), Malware (domain on a live threat-intelligence feed), Malicious (phishing/look-alike domains), Fake Domain (non-existent, disposable, or typo'd domains), and Undeliverable (no-reply mailboxes, impossible usernames, or an address a live SMTP check actually rejected). Each row also shows which company powers that email's mail server, with a link to it.

Built for scale: results are stored in a background database rather than kept in memory, so the table stays instant to scroll and filter even at millions of rows. DNS lookups run once per unique domain, in parallel, rather than once per address.

Clean-up tools: filter the results with one click per issue, clear invalid addresses (either everything invalid, or just specific issues you pick), and export either the clean list as .txt or the full annotated results as .csv. Anything cleared moves to a separate tab and can be restored.

Licensing: each copy activates to one machine via a signed license key with an expiry date. A 7-day warning appears before expiry; an expired, mismatched, or tampered license locks every action button until it's renewed or deactivated. An unlicensed copy runs in a capped trial mode.

Look and feel: dark, high-contrast interface (Catppuccin Mocha palette), from the same product family as MailScraperAI.