Postal

✓ Verified FOSSMIT

Top open-source alternative to Mailchimp

Postal is a full-featured open-source mail delivery platform for incoming and outgoing transactional and bulk email, featuring DKIM/SPF/DMARC management, webhook routing, and message retention.

Tech StackRuby, MariaDB, RabbitMQ, Docker

Self-Host DifficultyMedium

License ModelMIT

GitHub Repositorypostalserver/postal

Recommended VPS & Hardware Sizing

Estimated Hosting: $10 - $15/mo (e.g. Hetzner CPX21 or Linode)

Min RAM:2 GB

Rec RAM:4 GB

Compute:2 vCPU

Disk Space:25 GB SSD

Postal vs Mailchimp Comparison Matrix

Evaluation Criteria	Postal (Open Source)	Mailchimp (Proprietary)
Subscription Model	100% Free Self-Hosted (Unlimited Users)	Mailchimp Per-Seat / Usage Billing
Data Sovereignty	100% On-Premise / Your Own VPS	Stored on Mailchimp Proprietary Cloud
Source Code Audit	Open-Source (MIT)	Closed-Source Proprietary Blackbox

INTERACTIVE TCO MODELEstimated Rate: $185/user/mo

Financial Impact: Migrating from Mailchimp to Self-Hosted Postal

Detailed Stack Calculator →

Active Team Members / Seats: 25 Users

5 Users (Early Startup)50 Users (Scaleup)200 Users (Enterprise Org)

Mailchimp (Cloud SaaS)Per-Seat Tax

$55,500per year ($4,625/mo)

3-Year Spend:$166,500

* Excludes enterprise SSO add-ons & usage overages

Postal (Self-Hosted)Zero Per-Seat Fee

$120per year ($10/mo Linux VPS)

3-Year Compute:$360

* Commodity Hetzner / DigitalOcean compute instance

Cumulative 3-Year ROI+$166,140Net savings across 36 months (100% reduction)

Annual Free Cash:+$55,380/yr

Need C-Level Buy-In? Generate an instant ROI proposal memo to present to your CTO or CFO.

HEAD-TO-HEAD BATTLES // SIDE-BY-SIDE AUDIT

Compare Postal Head-to-Head

Custom Comparison Engine →

★ PRIMARY REPLACEMENTFOSS vs SaaS

Postalvs

Mailchimp

Comprehensive benchmark comparing Postal against proprietary Mailchimp licensing and features.

View Full Battle Report→

CommunicationPEER BENCHMARK

Listmonkvs

Mailchimp

Self-Hosted High-Speed Newsletter Server vs $350+/Mo Mailchimp Tier

Inspect Comparison→

CommunicationPEER BENCHMARK

Novuvs

Twilio / Courier

Unified Notification Infrastructure (In-App, Push, Email, SMS) vs High Platform Fees

Inspect Comparison→

Core Capabilities & Features

✓Full Outgoing & Incoming SMTP/HTTP API

✓Automated SPF, DKIM & Return-Path Checks

✓Real-Time Delivery Webhooks & Bounce Logs

✓Unlimited Email Volume on Your IP

Self-Host Postal with Docker Compose

Tweak configuration ports, secrets, and volumes live. Download or copy your ready-to-run container file:

1-Click Docker Compose Generator

Generate production-ready container definitions with customizable ports and volumes.

Select Open-Source Project:

PostalMIT

Complete open-source mail delivery server replacing SendGrid and Mailchimp

Difficulty: Medium16,858 ⭐

Configure Parameters

Host Port (PORT)

Public Base URL (APP_URL)

Application Secret Key (SECRET_KEY)

docker-compose.postal.yml

version: "3.8"
services:
  postal:
    image: ghcr.io/postalserver/postal:latest
    container_name: postal
    restart: unless-stopped
    ports:
      - "${PORT:-5000}:5000"
    environment:
      APP_URL: "${APP_URL:-http://localhost:5000}"
      SECRET_KEY: "${SECRET_KEY:-ossmatrix_prod_secret_2026}"
    volumes:
      - postal_data:/data

volumes:
  postal_data:

Frequently Asked Questions: Self-Hosting Postal

How do I self-host Postal using Docker Compose?

You can deploy Postal (postalserver/postal) on any Linux server by copying the docker-compose.yml template on this page, configuring your desired host port and persistent volume directory, and running 'docker compose up -d'.

How does Postal compare to Mailchimp?

Postal is an open-source, self-hosted alternative to Mailchimp built with Ruby, MariaDB, RabbitMQ, Docker. Unlike Mailchimp ($20 - $350+ / month), Postal has zero per-user licensing fees and keeps 100% of your data on your own infrastructure.

What are the minimum VPS RAM and CPU requirements for Postal?

For production self-hosting (Medium difficulty tier), we recommend at least 4 GB RAM (minimum 2 GB), 2 vCPU, and 25 GB SSD storage, which typically costs $10 - $15/mo (e.g. Hetzner CPX21 or Linode).

Is Postal free for commercial business use under the MIT license?

Yes. Distributed under the MIT license, Postal can be self-hosted internally by businesses and engineering teams of any size without per-seat royalties.

README INTEGRATION // REPO EMBED

Embed Official Postal Badge in GitHub README

Served locally from OSSMatrix with Cloudflare global edge caching. Real-time verified alternative status, zero third-party dependencies, sub-5ms load time.

Live Preview:

Markdown Embed (GitHub / GitLab)

[![OSSMatrix Alternative](https://ossmatrix.com/api/badge/postal)](https://ossmatrix.com/project/postal)

HTML Embed (Docs / Landing Pages)

<a href="https://ossmatrix.com/project/postal" target="_blank" rel="noopener noreferrer"><img src="https://ossmatrix.com/api/badge/postal" alt="Postal on OSSMatrix" /></a>

SIMILAR REPOSITORIES // PEER COMPARISON