MessagePit

An email and SMS testing tool for developers. Send test emails and SMS messages from your application and inspect them in a clean web UI — nothing reaches real inboxes or real phones.

MessagePit is a fork of Mailpit extended with a Twilio-compatible SMS ingest endpoint, an SMS inbox UI, and a dedicated SMS ingest server.

Features

• Email: SMTP server, web UI, REST API, WebSocket live updates, search, tagging, POP3 server
• SMS: Twilio-compatible HTTP ingest, SMS inbox with read/unread tracking, live WebSocket updates
• Shared: Multi-arch Docker image, optional HTTP basic auth, Prometheus metrics

Ports

Port	Protocol	Purpose
1025	SMTP	Email ingest (mirrors port 25)
1110	POP3	POP3 server (optional)
1775	HTTP	SMS ingest — Twilio-compatible (mirrors SMPP port 2775)
8025	HTTP	Web UI and management API

Quick Start

# Docker
docker run -p 1025:1025 -p 1775:1775 -p 8025:8025 ghcr.io/coreydaley/messagepit

# From source
make run

Open http://localhost:8025 in your browser.

SMS Integration

Point your application's Twilio SDK at the SMS ingest server instead of api.twilio.com:

http://localhost:1775

The SMS server implements the Twilio Messages API endpoint:

POST /2010-04-01/Accounts/{AccountSid}/Messages.json

Required form fields: From, To, Body.

Signature validation

If --sms-auth-token is set, the server validates the X-Twilio-Signature HMAC-SHA1 header on every inbound request. Leave it unset (the default) to accept all messages without validation — suitable for local development.

Building

Requires Go 1.21+ and Node 22+.

make run     # build UI + binary and run with dev defaults
make install # build UI + binary and install to $GOPATH/bin
make test    # run Go test suite
make ui      # build frontend assets only
make build   # compile the binary only (requires ui assets)

Configuration

All flags can also be set via environment variables (e.g. --smtp → MP_SMTP_BIND_ADDR, --sms → MP_SMS_BIND_ADDR).

Flag	Default	Description
--smtp	0.0.0.0:1025	SMTP bind address
--sms	0.0.0.0:1775	SMS ingest bind address
--listen	0.0.0.0:8025	HTTP UI/API bind address
--db	(in-memory)	SQLite database file path

Run messagepit --help for the full list.

API

The REST API is documented at http://localhost:8025/api/v1.

SMS endpoints:

Method	Path	Description
GET	/api/v1/sms/messages	List SMS messages
GET	/api/v1/sms/message/{id}	Get single SMS message
PUT	/api/v1/sms/message/{id}/read	Mark as read
DELETE	/api/v1/sms/message/{id}	Delete message
DELETE	/api/v1/sms/messages	Delete all messages

Docker

Images are published to the GitHub Container Registry on every push to main and on tagged releases:

docker pull ghcr.io/coreydaley/messagepit:latest

docker-compose example

services:
  messagepit:
    image: ghcr.io/coreydaley/messagepit:latest
    ports:
      - "1025:1025"   # SMTP
      - "1775:1775"   # SMS ingest
      - "8025:8025"   # Web UI
    environment:
      MP_DATABASE: /data/messagepit.db
    volumes:
      - messagepit_data:/data

volumes:
  messagepit_data:

License

MIT — see LICENSE.

Portions of this project are derived from Mailpit by Ralph Slooten, also MIT licensed.