# Transactional Email Sandbox & Setup | TrackMailer

> The developer-first email activation layer for preparing transactional messaging, recipient logic and measurable delivery.

Last reviewed: 30 August 2026

## Current status

The TrackMailer workspace, contacts, groups, saved filters, API-key management and Sandbox validation are available. Customer delivery, provider events and conversion attribution are not active.

## “Accepted” is not the same as delivered—and delivered is not the outcome.

A successful send request does not prove delivery, engagement or business impact.

## What exists now

- [Markdown](https://www.trackmailer.io/index.md): Move from message intent to trustworthy delivery and outcome evidence without exposing email secrets in the browser.
- [Documentation](https://docs.markengroup.cloud/trackmailer): Configure TrackMailer audiences, API keys, Sandbox validation and sender domains. Customer delivery remains unavailable in this documentation revision.
- [llms-full.txt](https://www.trackmailer.io/llms-full.txt)


## Language

- [English](https://www.trackmailer.io/llms.txt)
- [Deutsch](https://www.trackmailer.io/de/llms.txt)
- [Español](https://www.trackmailer.io/es/llms.txt)