Inside the ‘Mail Access 4K’ Combolist: 3,704 Inboxes Exposed

HEROIC analysts found a file titled "MAIL ACCESS 4K MIX VALID 100" uploaded to Telegram in June 2026. Despite the "4K" in its name, the verified record count is 3,704 email addresses paired with plaintext passwords and login URLs, sold under the "valid" label to signal the credentials had been checked and still worked at the time of upload. Why This Is Dangerous: This file is specifically marketed as "mail access," meaning it is meant to give buyers direct entry into people's email inboxes. Since the passwords are stored in plaintext, an attacker can log in immediately, no cracking required. What Was Exposed: The leak includes email addresses, plaintext passwords, and the login URLs of the mail services those accounts belong to. Why This Matters: Access to an email inbox is one of the most damaging things an attacker can get, since most "forgot password" links for banking, shopping, and social media accounts get sent straight to that inbox. If your email is in this file, an attacker could use it to reset passwords on nearly every other account you own. How a Combolist Leak Like This Works: This type of file, sometimes called a "mail access" list, is a combolist specifically curated and tested to confirm the email logins still work, which is why it's labeled "valid." These lists are compiled from stealer malware logs, phishing kits, and older breaches, then verified and resold on Telegram to buyers looking for working inbox access. Check If You Are Affected: Because this file targets email access directly, checking your exposure is especially important. HEROIC's free breach scanner searches over 400 billion leaked records, including combolists like this one, and tells you immediately if your inbox needs a new password.