Your email.
Your server.
Your rules.

Koder Postal is a complete, self-hosted email server. Send, receive, and manage email with full ownership of your infrastructure — no third-party relays, no data harvesting, no limits.

koder-postal
$ dig MX koder.dev +short
10 postal.koder.dev.
$ openssl s_client -connect postal.koder.dev:465
CONNECTED
subject=CN = postal.koder.dev
issuer=C = US, O = Let's Encrypt
$ curl -s https://postal.koder.dev/health
{"status":"ok","smtp":true,"imap":true,"jmap":true}
$ systemctl status stalwart-mail
● stalwart-mail.service — Koder Postal
Active: active (running)
Memory: 48.2M CPU: 0.3%
25 / 465 / 587
SMTP
Send & receive
143 / 993
IMAP
Client access
HTTPS
JMAP
Modern API
HTTPS
Web Admin
Management UI

A full email server in a single binary

Powered by Stalwart Mail Server. Everything you need to run production email, with zero external dependencies.

SMTP Sending & Receiving

Full MTA with support for ports 25, 465 (implicit TLS), and 587 (STARTTLS). Deliver and receive emails directly — no relay needed.

IMAP Mailbox Access

Connect Thunderbird, Apple Mail, Outlook, or any IMAP client. Secure access via ports 143 (STARTTLS) and 993 (TLS).

JMAP — Modern Protocol

HTTP/JSON-based email access. Faster sync, lower bandwidth, and push notifications. The successor to IMAP for modern apps.

DKIM / SPF / DMARC / ARC

Industry-standard email authentication out of the box. Every outgoing message is signed. Incoming messages are verified.

End-to-End Encryption

TLS everywhere — SMTP, IMAP, and JMAP all encrypted in transit. Your emails never travel in plaintext.

RocksDB Storage

Embedded high-performance storage. No external database required. Fast reads, efficient compression, minimal footprint.

Web Admin Panel

Built-in administration interface for managing accounts, domains, and server settings. No SSH required for day-to-day operations.

Multi-Account

Create and manage multiple email accounts per domain. Individual quotas, aliases, and forwarding rules for each user.

Programmatic Access

Send emails from your applications via JMAP API or standard SMTP. Perfect for transactional emails, notifications, and automation.

How it works

Koder Postal runs as a single Stalwart Mail Server process, handling all email protocols and storage in one place.

Clients
Koder Mail Web
Thunderbird / Outlook
Mobile Apps
Koder Services (API)
Koder Postal
SMTP
IMAP
JMAP
Web Admin
Internet
Inbound SMTP
Outbound Delivery
DNS (MX, SPF, DKIM)

Take control of your email infrastructure

Self-hosted, standards-compliant, and built for reliability. Deploy Koder Postal and stop depending on third-party email providers.