Mail-in-a-Box

hMailServer: A Lightweight Mail Server That Doesn’t Try to Be Clever Sometimes what you need is a simple, Windows-based mail server that just does SMTP, IMAP, and POP3 — and doesn’t get in the way. That’s exactly what hMailServer is. It’s not pretending to be groupware. It doesn’t care about chat, calendar, or drive sync. It just wants to deliver email, receive email, and do it with as little noise as possible.

Despite its compact size, it’s fully capable of handling multiple domains, custom ro

OS: Windows / Linux / macOS
Size: 56 MB
Version: 73
🡣: 14,698 stars

hMailServer: A Lightweight Mail Server That Doesn’t Try to Be Clever

Sometimes what you need is a simple, Windows-based mail server that just does SMTP, IMAP, and POP3 — and doesn’t get in the way. That’s exactly what hMailServer is. It’s not pretending to be groupware. It doesn’t care about chat, calendar, or drive sync. It just wants to deliver email, receive email, and do it with as little noise as possible.

Despite its compact size, it’s fully capable of handling multiple domains, custom routes, spam protection, and external relay setups. For small businesses, dev teams, labs, or internal systems — it’s one of the few self-hosted mail servers that actually works on Windows without feeling hacked together.

No license, no cost, no catch.

What It Handles

Feature What It Actually Does
SMTP, IMAP, POP3 Full mail stack — send, receive, and fetch
Domain & Account Support Manage multiple domains and individual mailboxes
Built-In Anti-Spam DNSBL, SPF, greylisting, and custom spam rules
External Relay Option Can deliver mail through upstream SMTP (e.g., ISP or cloud provider)
Scripting Support Built-in VBScript engine for custom rules and event handling
SQL Backend Uses MySQL, MSSQL, or built-in DB for mail storage
ClamAV & SpamAssassin Integrates with popular antivirus/spam tools via command-line interfaces
WebAdmin Interface Optional web-based management portal
Logging & Debugging Detailed logging for troubleshooting mail flow
Free & Open Source Completely free under GPL — no paid edition

Why Admins Still Use It

It’s not new. It’s not flashy. But hMailServer is still one of the easiest ways to run a mail server on a Windows box — especially in places where Linux isn’t an option.

Admins reach for it when:
– They need internal email between systems or departments
– SMTP relay is required from web apps or internal services
– A dev/test environment needs real email behavior without cloud dependencies
– Email is hosted elsewhere, but filtering/routing needs to be done locally
– Compliance or company policy rules out hosted solutions

For simple tasks — especially on Windows Server — it does the job cleanly and predictably.

How to Set It Up

1. Download the latest build from:
→ https://www.hmailserver.com/

2. Install the service and choose a database (built-in or external)

3. Launch hMailServer Administrator and connect to `localhost`

4. Create a domain (e.g., `internal.lan`) and add user accounts

5. Configure SMTP, POP3, IMAP ports — adjust for firewall or ISP restrictions

6. Set up DNS (MX, SPF) if you’ll be receiving mail from the internet

7. Optional: Integrate SpamAssassin or ClamAV if needed

That’s it — no wizards, but no mystery either. All settings are clearly exposed.

Good to Know

– Logs are incredibly helpful — SMTP conversation, delivery, error logs all separate
– For small setups, the built-in database works fine
– SSL/TLS requires a valid certificate manually installed in Windows
– Works well as a local-only mail server without internet access
– Still maintained by the community, though updates are infrequent

Final Thought

hMailServer isn’t the future of email. It’s the dependable option that’s still here — and still works. For Windows shops, closed networks, or internal tooling, it’s often the path of least resistance.

Not everything needs to be hosted in the cloud. Sometimes, a small, sturdy Windows service is all it takes.

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