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Hail

Add AI calls, SMS, and email to apps and AI agents through one API

EmailAuth: API KeyHTTPS: YesCORS: noStatus: alive

Last verified: November 12, 2026

Reliability

100% uptime: the documentation responded in 5 of 5 checks over the last 30 days. Median response time: 440 ms.

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At a glance

  • Authentication: API Key
  • HTTPS: Yes
  • CORS: No, call it from a server
  • Documentation: https://hail.so
// Fetch the docs page with cURL curl https://hail.so

History

  • November 12, 2026: last health check, responding
  • November 2, 2026: Added to the directory (imported from marcelscruz)

See every change to the directory →

More Email APIs

Looking for other Email APIs? Here are more free options in the same category:

  • Academic Email API — This API allows you to verify whether an email belongs to a recognized educational institution
  • Atomic Mail — Email for AI agents: programmatic inbox creation and send/receive over JMAP
  • Autentify Verify — Brazilian email verification: deliverable, undeliverable, risky or unknown, with the reason
  • B2B Email & Domain Scorer — Email verification: MX, disposable/free/role detection, typo fix and a keep/fix/drop action
  • Best Temp Mail — Disposable inboxes for automated email testing, with OTP extraction
  • Brevo (formerly Sendinblue) — A service that provides solutions relating to marketing and/or transactional email and/or SMS
  • Cloudmersive Validate — Validate email addresses, phone numbers, VAT numbers and domain names
  • Disban — Classify email domains as disposable, free, alias, testing or parked to block fake signups
  • DropMail — GraphQL API for creating and managing ephemeral e-mail inboxes
  • Email Spam Tester — Send a test message and get a spam score, 41 checks with RFC citations and a fix plan

View all Email APIs →