What is email permutation?
Also called: email pattern guessing, email permutator
Email permutation is generating the likely address formats for a person at a company, such as first.last@, flast@ and first@, from their name and the company domain. Each candidate is then verified to find the one that exists. It only works when the domain is not catch-all.
Companies tend to use one pattern for everyone, so guessing is reasonable. Guessing without checking is not: sending to ten permutations means nine hard bounces for every real address, which is a fast way to damage a sending domain.
Verification is what makes permutation safe, with one limit. On a catch-all domain every permutation is accepted, so the probe cannot tell you which one is real. The honest output there is that the pattern is unconfirmed.
When a domain is catch-all, the better evidence is an address for someone else at the same company: if a colleague is first.last@, the person you want probably is too.
Example
jane.smith@, jsmith@, jane@, janes@, smithj@, jane_smith@, then each one is checked over SMTP.How SimpleVerifier handles it
The email permutator generates the common patterns and verifies them, marking the domain as catch-all when the server accepts everything instead of picking a guess and calling it valid.
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By SimpleVerifier Team · Last reviewed 2026-10-13 · All 50 glossary terms