GraphQL API for creating and managing ephemeral e-mail inboxes.
DropMail API is a free Email API that requires no API key, is served over HTTPS and has unconfirmed CORS support.
Create a temporary email programmatically via our easy API. For 10 minutes or more. Unlimited mailbox size. Attachments allowed.
Details from dropmail.me.

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The DropMail API is provided by DropMail.me API (dropmail.me). Create a temporary email programmatically via our easy API. For 10 minutes or more. Unlimited mailbox size. Attachments allowed.
Yes. The DropMail API is listed in the Email category of the public-apis directory, which only includes APIs that are free or have a free tier. Check its documentation for rate limits and paid plans.
No. The DropMail API requires no authentication, so you can start making requests without signing up.
CORS support for the DropMail API is unknown. Test a request from the browser, and fall back to a server-side call if it is blocked.
Yes. The DropMail API is served over HTTPS, so it's safe to use in production.