SMTPfast

Overview

SMTPfast is a free public API in the Email category. Send transactional email, manage contacts and broadcasts, free 3,000 emails/month.

This API belongs to the Email category, a popular area of the free-API ecosystem for builders.

You can use this API in prototypes, side projects, and production applications — just keep the provider’s usage policy in mind.

Authentication

SMTPfast uses API key authentication. You will need to obtain a key before making requests:

1. Open the official documentation at the link below.
2. Look for the sign-up / API-key section and create an account.
3. Copy your key and send it with every request (the docs show the exact header or query parameter to use).

Keep the key server-side and never commit it to public repositories.

HTTPS & CORS

• HTTPS: supported — traffic to SMTPfast is encrypted, so it is safe to use from production apps.
• CORS: enabled — SMTPfast can be called directly from the browser without a proxy, which simplifies client-side integrations.

Getting Started

1. Read the official documentation: https://smtpfa.st/docs
2. Obtain an API key (see Authentication above).
3. Make a test request with curl or your favourite HTTP client, sending the key as documented.

Rate Limits & Notes

• Rate limits, quotas, and free-tier terms are defined by the provider — always check the official documentation for SMTPfast before scaling up.
• The upstream listing is community-maintained; fields like auth, HTTPS and CORS reflect the state at listing time and may change.

FAQ

Where do I get an API key for SMTPfast?

API keys are issued by the provider. Head to the official documentation (https://smtpfa.st/docs) and follow the sign-up / key section.