Email typo fixer

Where typos come from

A surprising share of undeliverable addresses were real people who mistyped their own email on a phone keyboard. The domain is where it goes wrong most often: gmai.com, gmial.com, gamil.com, hotmal.com, yahooo.com, outlok.com, and the endings .con, .cmo, .ocm and .comm. These addresses pass almost any syntax check, and many of the misspelt domains do not even exist, so the welcome email bounces, the person never hears from you, and the bounce counts against your sender reputation.

How the fixer works

Paste up to 100 addresses. Each one is parsed and its domain is compared against a list of around 45 popular mailbox providers worldwide using Damerau-Levenshtein distance, which counts insertions, deletions, substitutions and adjacent transpositions. A short domain must be within one edit of a known provider to be flagged; a longer one may be within two. Mangled top-level domains are handled separately, so gmail.cmo and gmail.con both resolve to gmail.com. Domains that already match a known provider exactly are left alone, and so are unfamiliar domains that are not close to anything, which keeps legitimate company domains from being "corrected" into something wrong. Every flagged row shows the full corrected address, and the whole table can be copied as CSV with the fix in its own column.

Catching typos at the source

Fixing a list is good; preventing the typo is better. The Verifyre form validation widget suggests the corrected domain under the field the moment a visitor pauses typing, so gmai.com becomes gmail.com with one tap before the form is submitted. The same suggestion comes back as didYouMean in the API, and the email checker offers it on every result. On a list that already exists, run the fixer first, apply the corrections, then verify the corrected addresses with the bulk verifier: a corrected address is only valuable if the mailbox actually exists.

Treat suggestions as suggestions. A handful of people genuinely own addresses at look-alike domains, so for high-value contacts confirm with the person rather than rewriting silently.