Email APIs let you send transactional emails, verify addresses, and manage mailing lists. Handle email delivery, validation, and inbox management without running your own mail servers.
Last verified: April 1, 2026
| Name | Description | Auth | HTTPS | CORS | Status |
|---|---|---|---|---|---|
| Cloudmersive Validate | Validate email addresses, phone numbers, VAT numbers and domain names | apikey | Yes | yes | alive |
| DropMail | GraphQL API for creating and managing ephemeral e-mail inboxes | none | Yes | unknown | alive |
| Email Validation | Validate email addresses for deliverability and spam | apikey | Yes | yes | alive |
| Guerrilla Mail | Disposable temporary Email addresses | none | Yes | unknown | alive |
| ImprovMX | API for free email forwarding service | apikey | Yes | unknown | alive |
| Kickbox | Email verification API | none | Yes | yes | alive |
| mail.gw | 10 Minute Mail | none | Yes | yes | alive |
| mail.tm | Temporary Email Service | none | Yes | yes | alive |
| mailboxlayer | Email address validation | apikey | Yes | unknown | alive |
| MailboxValidator | Validate email address to improve deliverability | apikey | Yes | unknown | alive |
| MailCheck.ai | Prevent users to sign up with temporary email addresses | none | Yes | unknown | alive |
| Mailtrap | A service for the safe testing of emails sent from the development and staging environments | apikey | Yes | unknown | dead |
| Sendgrid | A cloud-based SMTP provider that allows you to send emails without having to maintain email servers | apikey | Yes | unknown | alive |
| Sendinblue | A service that provides solutions relating to marketing and/or transactional email and/or SMS | apikey | Yes | unknown | dead |
| Verifier | Verifies that a given email is real | apikey | Yes | yes | dead |
6 of these APIs require no authentication — you can start making requests immediately without signing up for an account. Just pick one from the table above, check its documentation, and send your first request.
9 APIs in this category require a free API key. This usually means creating a free account on the provider's website and copying your key from the dashboard. The process typically takes less than a minute.
Not sure where to start? Look for APIs marked as "alive" in the status column — these were recently verified as working. For browser-based projects, check that the API supports CORS.
Yes, all APIs listed on API Bouncer have a free tier. Some are completely open (no sign-up needed), while others require a free account to get an API key. Free tiers typically have rate limits — check each API's documentation for specifics.
It depends on your needs. Consider: Do you need authentication or prefer no-auth? Does your project need CORS support for browser access? How many requests will you make? Start with a no-auth API to prototype quickly, then switch to a more feature-rich option if needed.
We run periodic health checks on all listed APIs. The "Status" column shows whether each API was responding at our last check. APIs marked as "alive" were recently verified. You can also test any API yourself using curl or our guides on testing APIs.
Most free APIs allow commercial use, but terms vary by provider. Always check the specific API's terms of service. Some APIs have separate free and commercial tiers with different rate limits.
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