Email · head-to-head
MailCheck.ai vs Sendinblue
MailCheck.ai has rebranded to UserCheck, but its original keyless lookup endpoint keeps working unchanged: pass an address and get back disposable, free-provider, MX, and domain-age signals in one JSON response, aimed at blocking throwaway signups. The rebranded product adds a free-to-start paid tier for higher-volume, authenticated use.
Sendinblue rebranded to Brevo in 2023, and its REST API still covers the same ground under the new name: transactional and marketing email, SMS, and contact/campaign management behind an API-key header. A free plan covers a daily email allowance before metered and subscription paid tiers.
| MailCheck.ai | Sendinblue | |
|---|---|---|
| Authentication | None | API Key |
| Pricing | freemium | freemium |
| Formats | JSON | JSON |
| CORS | yes | yes |
| HTTPS | Yes | Yes |
MailCheck.ai needs no API key, while Sendinblue requires API Key — pick MailCheck.ai to start without signup.