Use Case

Stop Losing 3% of Signups to Typos

gmial.com, yaho.com, outlok.com — your users make these mistakes every day. Most validators reject them. MailSentry tells you exactly what they meant.

No credit card · No overage charges · Credits never expire

The math nobody shows you

Every typo costs you a real user.

3-5%

of signups have email typos

300

lost activations per 10K signups

$15K+

annual revenue lost at $50 LTV

A regex check says “invalid” and the user bounces. MailSentry says “Did you mean john@gmail.com?” and you save the signup.

How it works

Four layers working together.

Each layer catches what the others miss. Together they give you a complete picture of every email entering your signup form.

1

Typo Correction

gmial.com → gmail.com. We check against 100+ common domains using Levenshtein distance. Your form shows ‘Did you mean?’ instead of ‘Invalid email.’

2

Disposable Detection

5,400+ throwaway domains blocked. Guerrillamail, Tempmail, Yopmail — caught before they waste your onboarding flow.

3

Syntax Validation

RFC 5322 compliant. Plus-addressing (user+tag@) accepted. Unicode/IDN domains handled via punycode. We don’t reject valid emails.

4

Gibberish Detection

asdfkjh38274@ gets flagged. Keyboard mashing, repeated characters, consonant clusters — classified by pattern type, not just a boolean.

Developer experience

One API call. Full picture.

POST /api/v1/verify
curl -X POST https://mailsentry.dev/api/v1/verify \
  -H "X-API-Key: ms_live_..." \
  -H "Content-Type: application/json" \
  -d '{"email": "john@gmial.com"}'
Response
{
  "score": 15,
  "verdict": "invalid",
  "warning": "Possible typo detected",
  "checks": {
    "typo": { "has_typo": true, "suggestion": "john@gmail.com" },
    "disposable": { "is_disposable": false, "list_updated": "2026-04-26" },
    "syntax": { "valid": true, "plus_alias": null },
    "gibberish": { "is_gibberish": false, "pattern": null }
  }
}

The typo.suggestion field gives you everything you need to build a “Did you mean?” UI. One call, one field, zero complexity.

signup-form.js
const result = await fetch('/api/v1/verify', {
  method: 'POST',
  headers: { 'X-API-Key': 'ms_live_...', 'Content-Type': 'application/json' },
  body: JSON.stringify({ email: input.value })
}).then(r => r.json())

if (result.checks.typo.has_typo) {
  showPrompt(`Did you mean ${result.checks.typo.suggestion}?`)
}

Comparison

What other validators do with typos.

Feature
MailSentry
ZeroBounceNeverBounce
Typo correctionAutomatic + suggestionStandardAutomatic
Disposable list size5,400+Not publishedNot published
Plus-addressingAcceptedAcceptedAccepted
Gibberish detectionPattern classifiedNot availableNot available
Free plan1,000/mo recurring100/mo1,000 one-time

Stop bad emails. Pay 80% less.

1,000 free checks/moNo credit card≤3% bounce guarantee