How to check company email addresses for data breaches
2 min read · Updated October 15, 2026
List the email addresses and domains your business uses, run them through a breach lookup or a corporate audit, review which addresses and incidents appear and then act: reset exposed credentials, enforce two-factor authentication and warn staff about targeted phishing. Repeat the check regularly.
Why companies should check
Employees sign up for outside services with work emails all the time: SaaS tools, conferences, forums. When those services are breached, the work address and sometimes a reused password end up in leaked data, even though your own systems were never touched.
What to check
- ✓Individual employee addresses, starting with finance, IT, executives and admins.
- ✓Shared and role-based mailboxes such as info@, accounts@ and support@.
- ✓Your company domain overall, to see the scale of exposure.
- ✓Former employees’ addresses that may still be active or forwarded.
See how exposed your team’s email is
Leaked work emails fuel phishing and account takeover. Review your company’s exposure with a corporate audit.
How to read the results
Look for patterns: which services keep appearing, which dates, which data types. Passwords in a breach matter most. High-privilege accounts with exposed credentials come first. Treat matches as risk signals, not proof of compromise.
What to do next
- ✓Force password resets on exposed accounts and require unique passwords.
- ✓Make two-factor authentication mandatory, starting with email and admin tools.
- ✓Brief exposed staff on targeted phishing and payment-change fraud.
- ✓Set a routine to repeat the check, for example every quarter.
A simple company breach check process
- 1Export the list of company email addresses and role mailboxes.
- 2Run them through a breach lookup or a corporate audit.
- 3Rank exposures by privilege and data type.
- 4Reset passwords and enforce 2FA for exposed accounts.
- 5Notify affected staff with clear instructions.
- 6Schedule the next review.
Frequently asked questions
Do we need employee consent?+
Rules vary by country and policy. Many companies cover this in their security policy. Check with your legal or compliance team.
Is a clean result enough?+
It is a good sign but not a guarantee. Combine it with MFA, training and monitoring.
How often should we check?+
Quarterly is a sensible starting point, and after any supplier breach announcement.
Stop guessing. Check your email in seconds.
The free Leakill check looks for your email address in known breach records and tells you whether it was exposed. If it was, an optional detailed report lists the incidents, dates, sources, the kinds of data involved and practical next steps. It is a one-off report, not a subscription.
A breach match is a warning signal, not proof that someone has access to your account today. No public database covers every breach, so a clean result lowers risk without guaranteeing safety.