From 1995 to 2019, I ran my own mail server. It began with a UUCP link, an expensive long-distance call for me then. Later, I ran a mail server in my apartment, then ran it as a VPS at various places.

But running an email server got difficult. You can’t just run it on a residential IP. Now there’s SPF, DKIM, DMARC, and TLS to worry about. I recently reviewed mail hosting services, and don’t get me wrong: I still use one, and probably will, because things like email from my bank are critical.

But we’ve lost the ability to tinker, to experiment, to have fun with email.

Not anymore. NNCPNET is an email system that runs atop NNCP. I’ve written a lot about NNCP, including a less-ambitious article about point-to-point email over NNCP 5 years ago. NNCP is to UUCP what ssh is to telnet: a modernization, with modern security and features. NNCP is an asynchronous, onion-routed, store-and-forward network. It can use as a transport anything from the Internet to a USB stick.

NNCPNET is a set of standards, scripts, and tools to facilitate a broader email network using NNCP as the transport. You can read more about NNCPNET on its wiki!

The “easy mode” is to use the Docker container (multi-arch, so you can use it on your Raspberry Pi) I provide, which bundles:

• Exim mail server
• NNCP
• Verification and routing tools I wrote. Because NNCP packets are encrypted and signed, we get sender verification “for free”; my tools ensure the From: header corresponds with the sending node.
• Automated nodelist tools; it will request daily nodelist updates and update its configurations accordingly, so new members can be communicated with
• Integration with the optional, opt-in Internet email bridge

It is open to all. The homepage has a more extensive list of features.

I even have mailing lists running on NNCPNET; see the interesting addresses page for more details.

There is extensive documentation, and of course the source to the whole thing is available.

The gateway to Internet SMTP mail is off by default, but can easily be enabled for any node. It is a full participant, in both directions, with SPF, DKIM, DMARC, and TLS.

You don’t need any inbound ports for any of this. You don’t need an always-on Internet connection. You don’t even need an Internet connection at all. You can run it from your laptop and still use Thunderbird to talk to it via its optional built-in IMAP server.