All tests and tools Self-check

Who will soon write in your name?

CEO fraud does not need your mailbox. A domain that looks almost like yours is enough: rnusterfirma.de instead of musterfirma.de. I check more than a hundred such variants and show which already exist. Pure DNS lookup, no sign-up.

The search takes a few seconds.

What is checked: other endings such as .com or .eu, confusable characters such as rn instead of m or 0 instead of o, umlaut spellings, missing, doubled or swapped letters, hyphens, additions such as "-online" and neighbouring keys. Variants with their own mail server are especially dangerous.

This check only reads public DNS records and stores nothing. It is also available as an open API and as an MCP tool.

Set up in an hour, trained in a week.

Create a free account, add your team, unlock the course. You only pay when you start. Would you rather see what a test email looks like first? The self-test is free.

Add your team Test it yourself first