Transactional Email API
Transactional Email API is a app in the osFoundry community catalog. Self-hosted transactional email — SMTP relay + HTTP API, deliverability tracking, bounce + click + open webhooks, multi-tenant credentials. Powered by Postal. Ships as a self-contained all-in-one image bundling Postal (Rails), MariaDB, and RabbitMQ.
Details
- Workspace: osfoundry
- Category: COMMUNICATION
- Pricing: Free
- Access: Community
Features
- Self-hosted transactional email — SMTP relay + HTTP API
- Deliverability tracking
- Bounce + click + open webhooks
- Multi-tenant credentials
Documentation
# Transactional Email API
Self-hosted transactional email infrastructure, powered by Postal. Drop-in alternative to SendGrid / Postmark / Mailgun APIs.
## Features
- SMTP relay (port 25 + submission 587)
- HTTP API for sending + status
- Bounce / click / open tracking + webhooks
- Multiple servers (tenants) under one install
- Suppression lists per server
## Packaging
All-in-one build: Postal (Rails web + smtp + worker + cron + requeuer) + bundled MariaDB + RabbitMQ under one supervisor on a persistent volume.
## Deliverability note
Getting mail delivered is half DNS, half IP reputation. You need: SPF + DKIM + DMARC for `POSTAL_SMTP_HOSTNAME`, a public PTR matching the egress IP, and an IP that isn't on RBLs. Some cloud providers (including DigitalOcean) block outbound port 25 by default — request unblock or use a smart-host relay.
How to use Transactional Email API in osFoundry
Install Transactional Email API into your workspace in one click, then fork it in osStudio to customise the prompts, tools, or configuration for your stack. Anyone in your workspace can pick up where you left off.
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