Sending emails (Mailtrap)

Overview

Mailtrap sends live email over Email API (REST) or SMTP. Two streams apply for API/SMTP: Transactional (non-promotional, app-generated) and Bulk (promotional / marketing volume). Batch is not a third stream: it is how you submit many messages in one request on whichever stream matches the content. Campaigns are a separate product path for promotional mail to Mailtrap contacts. Pair this sheet with the Transactional / Bulk developer pages when building or debugging integrations (including with AI-assisted coding).

When to Use

Use when integrating, configuring, or troubleshooting Mailtrap live email sending with Email API, SMTP, transactional streams, bulk streams, or batch requests.

Sending authority and delivery checks

Live send examples deliver externally. Before any send, confirm the approved sender, exact recipient list, final content/template variables, stream and message count. Integration or troubleshooting alone does not authorize sending. Use the sandbox for tests unless live delivery is requested; do not treat example recipients as real targets. Keep tokens out of logged process arguments (use protected header stdin/config or the SDK), redact responses, and check delivery state before retrying an uncertain POST to avoid duplicate mail. Account limits and suppression behavior require current docs; do not bypass unsubscribes or suppressions.

How to integrate (preference order)

Preferred order: