Asynchronous Email: Exim over NNCP (or UUCP)

Following up to yesterday’s article about how NNCP rehabilitates asynchronous communication with modern encryption and onion routing, here is the first of my posts showing how to put it into action.

Email is a natural fit for async; in fact, much of early email was carried by UUCP. It is useful for an airgapped machine to be able to send back messages; errors from cron, results of handling incoming data, disk space alerts, etc. (Of course, this would apply to a non-airgapped machine also).

The NNCP documentation already describes how to do this for Postfix. Here I will show how to do it for Exim.

A quick detour to UUCP land

When you encounter a system such as email that has instructions for doing something via UUCP, that should be an alert to you that “here is some very relevant information for doing this same thing via NNCP.” The syntax is different, but broadly, here’s a table of similar NNCP commands:

Purpose UUCP NNCP
Connect to remote system uucico -s, uupoll nncp-call, nncp-caller
Receive connection (pipe, daemon, etc) uucico (-l or similar) nncp-daemon
Request remote execution, stdin piped in uux nncp-exec
Copy file to remote machine uucp nncp-file
Copy file from remote machine uucp nncp-freq
Process received requests uuxqt nncp-toss
Move outbound requests to dir (for USB stick, airgap, etc) N/A nncp-xfer
Create streaming package of outbound requests N/A nncp-bundle

If you used UUCP back in the day, you surely remember bang paths. I will not be using those here. NNCP handles routing itself, rather than making the MTA be aware of the network topology, so this simplifies things considerably.

Sending from Exim to a smarthost

One common use for async email is from a satellite system: one that doesn’t receive mail, or have local mailboxes, but just needs to get email out to the Internet. This is a common situation even for conventionally-connected systems; in Exim speak, this is a “satellite system that routes mail via a smarthost.” That is, every outbound message goes to a specific target, which then is responsible for eventual delivery (over the Internet, LAN, whatever).

This is fairly simple in Exim.

We actually have two choices for how to do this: bsmtp or rmail mode. bsmtp (batch SMTP) is the more modern way, and is essentially a derivative of SMTP that explicitly can be queued asynchronously. Basically it’s a set of SMTP commands that can be saved in a file. The alternative is “rmail” (which is just an alias for sendmail these days), where the data is piped to rmail/sendmail with the recipients given on the command line. Both can work with Exim and NNCP, but because we’re doing shiny new things, we’ll use bsmtp.

These instructions are loosely based on the Using outgoing BSMTP with Exim HOWTO. Some of these may assume Debianness in the configuration, but should be easily enough extrapolated to other configs as well.

First, configure Exim to use satellite mode with minimal DNS lookups (assuming that you may not have working DNS anyhow).

Then, in the Exim primary router section for smarthost (router/200_exim4-config_primary in Debian split configurations), just change transport = remote_smtp_smarthost to transport = nncp.

Now, define the NNCP transport. If you are on Debian, you might name this transports/40_exim4-config_local_nncp:

nncp:
  debug_print = "T: nncp transport for $local_part@$domain"
  driver = pipe
  user = nncp
  batch_max = 100
  use_bsmtp
  command = /usr/local/nncp/bin/nncp-exec -noprogress -quiet hostname_goes_here rsmtp
.ifdef REMOTE_SMTP_HEADERS_REWRITE
  headers_rewrite = REMOTE_SMTP_HEADERS_REWRITE
.endif
.ifdef REMOTE_SMTP_RETURN_PATH
  return_path = REMOTE_SMTP_RETURN_PATH
.endif

This is pretty straightforward. We pipe to nncp-exec, run it as the nncp user. nncp-exec sends it to a target node and runs whatever that node has called rsmtp (the command to receive bsmtp data). When the target node processes the request, it will run the configured command and pipe the data in to it.

More complicated: Routing to various NNCP nodes

Perhaps you would like to be able to send mail directly to various NNCP nodes. There are a lot of ways to do that.

Fundamentally, you will need a setup similar to the UUCP example in Exim’s manualroute manual, which lets you define how to reach various hosts via UUCP/NNCP. Perhaps you have a star topology (every NNCP node exchanges email with a central hub). In the NNCP world, you have two choices of how you do this. You could, at the Exim level, make the central hub the smarthost for all the side nodes, and let it redistribute mail. That would work, but requires decrypting messages at the hub to let Exim process. The other alternative is to configure NNCP to just send to the destinations via the central hub; that takes advantage of onion routing and doesn’t require any Exim processing at the central hub at all.

Receiving mail from NNCP

On the receiving side, first you need to configure NNCP to authorize the execution of a mail program. In the section of your receiving host where you set the permissions for the client, include something like this:

      exec: {
        rsmtp: ["/usr/sbin/sendmail", "-bS"]
      }

The -bS option is what tells Exim to receive BSMTP on stdin.

Now, you need to tell Exim that nncp is a trusted user (able to set From headers arbitrarily). Assuming you are running NNCP as the nncp user, then add MAIN_TRUSTED_USERS = nncp to a file such as /etc/exim4/conf.d/main/01_exim4-config_local-nncp. That’s it!

Some hosts, of course, both send and receive mail via NNCP and will need configurations for both.

When You Think You’re At the End, You’re At the Beginning

Often when you think you’re at the end of something, you’re at the beginning of something else.

– Fred Rogers

This is sunrise over Kansas. Or maybe sunset. I’m not going to tell you this time, because it doesn’t matter all that much. I love that it (if you don’t over-analyze it) could be either, and also that it looks like the land in the distance fades to a blue ocean.

Is it sunrise or sunset? What is at the horizon? I don’t think it really matters, in the presence of such natural beauty.

Rural Kansas, 2015

Rehabilitating Asynchronous Communication with NNCP: A Cross Between Tor, ssh, and UUCP

Have you ever been traveling, shot a ton of photos and videos, but were annoyed to find it was saturating the terrible wifi you had access to? Maybe you’d wish the upload to pause until you get somewhere else, but then pausing syncing on your Nextcloud/Syncthing/Dropbox would also pause other syncing you didn’t want to pause. Or you have trouble backing up your laptop when not at home, in a way that won’t accidentaly eat up your cell phone data.

There are ways to help with this: asynchronous transfer.

Here’s a lot of background. If you want to see how encrypted, onion-routed UUCP looks, skip ahead to the “NNCP” section!

There is an old saying: “When all you have is a hammer, every problem looks like a nail.” We have this wonderful tool called ssh available, and it is pervasive and well-understood, so we tend to use it. But we’ve missed out on some benefits of asynchronous processing that we actually used to have more frequently.

Of course, we are all used to some asynchronous services in our lives. Email is a popular example: most mail clients work offline and will transmit stored messages when the mail server becomes reachable. Mail servers themselves work that way, too. Many instant messaging platforms do as well.

Even some backup systems do. Bacula/Bareos, for instance, spools all backup data to disk on the system connected to the tape drive, and from there to the tape itself. They do this for several reasons, but primarily the fact that if tape drives are not fed with data at their design speed, it can cause physical damage to the tape or even the drive. It causes the drive to have to pause, and seek backwards to reposition for the next write. This creates excessive travel of the tape over the write heads, causing a condition known as “tape shine” where the tape is damaged prematurely.

Here are some problems people often run into when sending data across a network (or the Internet) synchronously:

  • One side of the communication is much faster than the other
  • Internet issues interrupting communications mid-stream
  • Slow Internet causing processes to take much longer than planned, resulting in unexpected results or locking issues
  • Physical damage due to performance issues

Of course, there are plenty of situations where synchronous communication is a must. For instance:

  • When the status of the transaction at the remote end must be known immediately
  • When there is insufficient space to spool a job’s data

I suspect that the reason we don’t do more asynchronous processing these days, despite it being strong in the Unix heritage, is the lack of modern tools to do it. Let’s explore some more.

Some of my use cases

I run ZFS on all my systems that support it: file server, laptops, workstations, etc. It is only natural to use ZFS send/receive to do backups, and I do. However, when I am traveling, my laptop never gets backed up, because the backups are pulled from the backup system. Sure, there are ways around that; a VPN, for instance. But then we have the situation where sometimes I do not want to send the backup even if I have a working Internet connection: perhaps I’m tethered to a mobile connection and it would be expensive to do so, or I’m on hotel Wifi that is flaky and slow and I don’t want to give up any of its meager bandwidth.

I have another backup-related problem. I have a remote server, which until recently was using extremely slow disks. If I made significant changes, the backup would take the better part of a day. That’s annoying when I try to back up hourly. So of course I had to implement locking, but then that means none of my other machines would back up that day either.

Once I needed to transmit about 2TB of data. My home Internet connection was terribly slow, and I calculated it would take multiple months to do this. So I took to manually copying parts of the data to my laptop, and whenever I’d find an airport or coffee shop with faster Internet than at home, I’d send off those bits from it. But it took a ton of work.

The bespoke asynchronous problem

And that “ton of work” is perhaps why we aren’t doing more of this. There’s been no great standard solution, so it’s all “roll your own” when you need to. So we just use ssh, because it’s easier and usually “good enough”. But as I wrote in my recent article on airgapped backups, there are reasons to go async.

Solutions

Wouldn’t it be great to be able to queue up data for a machine, and let it get there in whatever way it can? Maybe a fast Internet connection is found, or via Tor, or via copying to a USB stick, or via radio broadcast? It would make many of these scenarios a lot easier. And there are ways for this now, with modern security!

We have some tools on Linux for this: git-annex for storage and migration, syrep for synchronization, and NNCP for file transfer and remote execution (could be combined with some of these other tools). Let’s dive in to NNCP.

NNCP

If you already know UUCP, think of NNCP as UUCP brought into the modern era, with modern security and tools.

Basically, NNCP permits you to send files to a remote system, request files from a remote system, and pipe data to an NNCP command that requests execution remotely. So you could, say, pipe a zfs send to NNCP which sends it to the remote and pipes it to zfs receive when it gets there.

NNCP has a delay-tolerant, resumable protocol that can run over just about any reliable connection: TCP, serial, Tor, radios of various kinds, you name it. But that’s not all; it also can dump its queue onto something like a USB stick for transport, or even make a tar-style stream that could be munged however you like. If you want to get fancy, you can assign priorities to data packets, so that, for instance, outbound email will always get sent before that 1TB file you’ve got to send also. You can also configure it so that certain carriers handle certain priorities of data; your cell phone would only handle the most urgent, but a USB stick would take anything.

NNCP is source-routed; you can tell it that the way that Bob reaches Alice is via Carl, then Betty. Bob can generate a message that will be sent along that route, fully encrypted and authenticated at each step of the way; Carl can’t see the content of the message or even anything about it other than its next hop.

How this helps

Let’s revisit some of my scnearios with NNCP.

For the laptop being backed up, while traveling it can queue up its backups, or photos, or videos, or whatever. They could be triggered by a command when on a good connection, or automatically. The data could be copied to USB and given to a friend to transmit; perfectly safe due to encryption. Or it could all wait until arriving at home, safely out of your other syncing directories. The NNCP documentation has an example of this.

For the server being backed up slowly, that’s easily solved; the slow backup would simply be queued up, and transmitted and processed when it’s ready. This wouldn’t interrupt other backups.

How about the 2TB transmission problem? That’s also made a lot easier. A command could be run to fill up a USB stick with parts of the queue, then that USB stick plugged in and transmitted whenever at a fast location. Repeat as needed while the slow system continues its upload of the remaining bits.

NNCP has a lot of interesting use cases documented as well.

If you are already familiar with how public keys work in SSH, then NNCP should be immediately familiar as well. It is a similar concept (though arguably somewhat easier to set up).

I am working on setting up a NNCP network, and will have more posts on how to do so once I’ve got it going. In the meantime, the documentation for the project is also pretty good.

So Many Caring People In This World

When I was a boy and I would see scary things in the news, my mother would say to me, “Look for the helpers. You will always find people who are helping.” To this day, especially in times of “disaster,” I remember my mother’s words and I am always comforted by realizing that there are still so many helpers – so many caring people in this world.

– Fred Rogers

This photo doesn’t have amazing lighting or fantastic composition. In fact, it looks ordinary. It’s only when you know its story that the beauty shines through.

In 2019, Fremont, NE had been cut off by flooding. People were trying to get in and out of the town, and couldn’t. The only way in or out was from the small airport. About 50 pilots from Nebraska and Iowa (and me from Kansas) came over to help. Every plane you see here — and more that I couldn’t fit in the frame — was at Millard Airport, Omaha, flying people and supplies into and out of Fremont. Estimates are that we flew over 1000 people and tons of supplies that weekend. All safely.

I remember flying the family with a 1-week-old baby that had gone to Omaha for a doctor appointment and then couldn’t get home for three days. I remember the elderly couple and their dog that I flew out of Fremont, the former Marine riding in the co-pilot seat next to me, cracking jokes with me as we went. I remember the group of ladies that were laughing as I gave them the required seat belt briefing, the mom with her kids, the man that had to get to work, and packed a few day’s supplies in his backpack, unsure when he’d be able to get back home. It was the first some had ever been in a plane.

There were so many helpers. People all over Omaha brought supplies to Millard airport. Others had just shown up at both airports to help organize and make lists of passengers and match them up with different size planes. Someone at Millard had a trailer and golf cart for supplies. When I’d land at Fremont, before I was even out of the plane, highschoolers had already swarmed it and were helping to unload supplies or help passengers out. One time when I got back to Millard, I found lunch: a pizza place had donated pizza for the pilots, and then a restaurant in Fremont did too. With so many extra planes in the sky, Omaha ATC was slammed and still did a fantastic job.

I of course took no photos of the people I carried, but I have thought of them often in the last year.

This photo is of Millard airport, Omaha, loading up supplies. Look at all these helpers. I think it’s one of the most beautiful sights I’ve ever seen.

Today there are billions of helpers in this world. The obvious ones: the truck drivers, the health care workers, the grocery store workers. And also the non-obvious ones: all the people that are wearing masks, practicing social distancing, forgoing Christmas gatherings, for the good of others, despite the hardship and heartbreak it may cause.

If you didn’t know the story of this photo, you wouldn’t know these planes were all helpers in time of disaster. We don’t know the story of all the people we see in our world today, but chances are good that many of them are helpers also.

When you know their story, the beauty shines through.

May we all be able to see the beauty that still surrounds us this Christmas.

Joyful is the Dark

“Joyful is the dark
  coolness of the tomb,
waiting for the wonder
  of the morning.

Never was that midnight
  touched by dread and gloom;
darkness was the cradle
  of the dawning.”

Brian Wren

Most of us are not personally experiencing symptoms of a pandemic virus, but with all the changes around us, with all the worries within us, many of us have been touched by dread and gloom.

I can find many layers of meaning in this poem. Today I think this poem excerpt reminds us to find the joy where we are, in the moment we are. Are we just waiting for the morning? Or do we take advantage of this pause to gaze up at the beautiful colors of the night? Are we defined by this moment, or do we define it? We are OK right now, so let this time be the cradle of something beautiful.

If you haven’t noticed the moon in this photo, zoom in. I don’t see dread and gloom in this photo. I see color, and hope, and beauty.

Rural Kansas, 2017

O, Sunlight!

“O, Sunlight! The most precious gold to be found on Earth.”

– Roman Payne

There is much beauty in this world, much hope, much life. All we need to do is pause, breathe, and take a moment to see it. It might be as simple as the gift of sunlight. I hope you all have moments of sunlight and delight each day.

Marion County, KS, April 2013

How & Why To Use Airgapped Backups

A good backup strategy needs to consider various threats to the integrity of data. For instance:

  • Building catches fire
  • Accidental deletion
  • Equipment failure
  • Security incident / malware / compromise

It’s that last one that is of particular interest today. A lot of backup strategies are such that if a user (or administrator) has their local account or network compromised, their backups could very well be destroyed as well. For instance, do you ssh from the account being backed up to the system holding the backups? Or rsync using a keypair stored on it? Or access S3 buckets, etc? It is trivially easy in many of these schemes to totally ruin cloud-based backups, or even some other schemes. rsync can be run with –delete (and often is, to prune remotes), S3 buckets can be deleted, etc. And even if you try to lock down an over-network backup to be append-only, still there are vectors for attack (ssh credentials, OpenSSL bugs, etc). In this post, I try to explore how we can protect against them and still retain some modern conveniences.

A backup scheme also needs to make a balance between:

  • Cost
  • Security
  • Accessibility
  • Efficiency (of time, bandwidth, storage, etc)

My story so far…

About 20 years ago, I had an Exabyte tape drive, with the amazing capacity of 7GB per tape! Eventually as disk prices fell, I had external disks plugged in to a server, and would periodically rotate them offsite. I’ve also had various combinations of partial or complete offsite copies over the Internet as well. I have around 6TB of data to back up (after compression), a figure that is growing somewhat rapidly as I digitize some old family recordings and videos.

Since I last wrote about backups 5 years ago, my scheme has been largely unchanged; at present I use ZFS for local and to-disk backups and borg for the copies over the Internet.

Let’s take a look at some options that could make this better.

Tape

The original airgapped backup. You back up to a tape, then you take the (fairly cheap) tape out of the drive and put in another one. In cost per GB, tape is probably the cheapest medium out there. But of course it has its drawbacks.

Let’s start with cost. To get a drive that can handle capacities of what I’d be needing, at least LTO-6 (2.5TB per tape) would be needed, if not LTO-7 (6TB). New, these drives cost several thousand dollars, plus they need LVD SCSI or Fibre Channel cards. You’re not going to be hanging one off a Raspberry Pi; these things need a real server with enterprise-style connectivity. If you’re particularly lucky, you might find an LTO-6 drive for as low as $500 on eBay. Then there are tapes. A 10-pack of LTO-6 tapes runs more than $200, and provides a total capacity of 25TB – sufficient for these needs (note that, of course, you need to have at least double the actual space of the data, to account for multiple full backups in a set). A 5-pack of LTO-7 tapes is a little more expensive, while providing more storage.

So all-in, this is going to be — in the best possible scenario — nearly $1000, and possibly a lot more. For a large company with many TB of storage, the initial costs can be defrayed due to the cheaper media, but for a home user, not so much.

Consider that 8TB hard drives can be found for $150 – $200. A pair of them (for redundancy) would run $300-400, and then you have all the other benefits of disk (quicker access, etc.) Plus they can be driven by something as cheap as a Raspberry Pi.

Fancier tape setups involve auto-changers, but then you’re not really airgapped, are you? (If you leave all your tapes in the changer, they can generally be selected and overwritten, barring things like hardware WORM).

As useful as tape is, for this project, it would simply be way more expensive than disk-based options.

Fundamentals of disk-based airgapping

The fundamental thing we need to address with disk-based airgapping is that the machines being backed up have no real-time contact with the backup storage system. This rules out most solutions out there, that want to sync by comparing local state with remote state. If one is willing to throw storage efficiency out the window — maybe practical for very small data sets — one could just send a full backup daily. But in reality, what is more likely needed is a way to store a local proxy for the remote state. Then a “runner” device (a USB stick, disk, etc) could be plugged into the network, filled with queued data, then plugged into the backup system to have the data dequeued and processed.

Some may be tempted to short-circuit this and just plug external disks into a backup system. I’ve done that for a long time. This is, however, a risk, because it makes those disks vulnerable to whatever may be attacking the local system (anything from lightning to ransomware).

ZFS

ZFS is, it should be no surprise, particularly well suited for this. zfs send/receive can send an incremental stream that represents a delta between two checkpoints (snapshots or bookmarks) on a filesystem. It can do this very efficiently, much more so than walking an entire filesystem tree.

Additionally, with the recent addition of ZFS crypto to ZFS on Linux, the replication stream can optionally reflect the encrypted data. Yes, as long as you don’t need to mount them, you can mostly work with ZFS datasets on an encrypted basis, and can directly tell zfs send to just send the encrypted data instead of the decrypted data.

The downside of ZFS is the resource requirements at the destination, which in terms of RAM are higher than most of the older Raspberry Pi-style devices. Still, one could perhaps just save off zfs send streams and restore them later if need be, but that implies a periodic resend of a full stream, an inefficient operation. dedpulicating software such as borg could be used on those streams (though with less effectiveness if they’re encrypted).

Tar

Perhaps surprisingly, tar in listed incremental mode can solve this problem for non-ZFS users. It will keep a local cache of the state of the filesystem as of the time of the last run of tar, and can generate new tarballs that reflect the changes since the previous run (even deletions). This can achieve a similar result to the ZFS send/receive, though in a much less elegant way.

Bacula / Bareos

Bacula (and its fork Bareos) both have support for a FIFO destination. Theoretically this could be used to queue of data for transfer to the airgapped machine. This support is very poorly documented in both and is rumored to have bitrotted, however.

rdiff and xdelta

rdiff and xdelta can be used as sort of a non-real-time rsync, at least on a per-file basis. Theoretically, one could generate a full backup (with tar, ZFS send, or whatever), take an rdiff signature, and send over the file while keeping the signature. On the next run, another full backup is piped into rdiff, and on the basis of the signature file of the old and the new data, it produces a binary patch that can be queued for the backup target to update its stored copy of the file.

This leaves history preservation as an exercise to be undertaken on the backup target. It may not necessarily be easy and may not be efficient.

rsync batches

rsync can be used to compute a delta between two directory trees and express this as a single-file batch that can be processed by a remote rsync. Unfortunately this implies the sender must always keep an old tree around (barring a solution such as ZFS snapshots) in order to compute the delta, and of course it still implies the need for history processing on the remote.

Getting the Data There

OK, so you’ve got an airgapped system, some sort of “runner” device for your sneakernet (USB stick, hard drive, etc). Now what?

Obviously you could just copy data on the runner and move it back off at the backup target. But a tool like NNCP (sort of a modernized UUCP) offer a lot of help in automating the process, returning error reports, etc. NNCP can be used online over TCP, over reliable serial links, over ssh, with offline onion routing via intermediaries or directly, etc.

Imagine having an airgapped machine at a different location you go to frequently (workplace, friend, etc). Before leaving, you put a USB stick in your pocket. When you get there, you pop it in. It’s despooled and processed while you want, and return emails or whatever are queued up to be sent when you get back home. Not bad, eh?

Future installment…

I’m going to try some of these approaches and report back on my experiences in the next few weeks.

Every Storm Runs Out Of Rain

“Every storm runs out of rain.”

– Maya Angelou

There are a lot of rain clouds in life these days. May we all remember that days like this one are behind us — and also ahead of us.

Every storm runs out of rain.


That was the start of a series of photos from my collection & quotes I shared with friends during the initial lockdown in spring. I’ll be sharing some here.

And here we all are, still dealing with this — and it’s more severe in a lot of ways. One of my colleagues won’t be able to see his parents this Christmas for the first time in over 40 years.

But this storm will run out rain.

And look how the scene changed, in just a few minutes. This is coming!

Non-Creepy Technology Purchasing & Gifting Guides

This time of year, a lot of people are thinking of buying gadgets and phones as gifts. But there are a lot of tech companies that have unethical practices, from terrible working conditions in their factories to spying on their users. Here are some buying guides to help you find gadgets that are fun – and not creepy.

The Free Software Foundation’s Ethical Tech Giving Guide is a fantastic resource from what’s probably the pickiest organization out there when it comes to tech. Not only do they highlight good devices, they also explain why and why you should, for instance, avoid the iPhone (their history of silencing political activists and spying on users).

The FSF also has a Guide to DRM-Free Living talks about books, video, audio, and software that respects your freedom by letting you make your own backups, move it to other devices, and continue to use your purchases even if you have no Internet or the company you bought them from goes bankrupt. This is a fantastic and HUGE resource; there are hundreds of organizations out there that provide content in a way that respects your rights — and many of them do it for free, legally, as well.

PrivacyTools has a fantastic series of guides on everything from email providers to operating systems, as well as links to a number of other guides.

The DeGoogle wiki on Reddit (as well as the sidebar) has a lot of fantastic alternatives to things like Chromebooks, Chrome, Gmail, etc.

Related resources

Here are some resources for education (what the issues are) and information about what companies and products to avoid.

In addition to the FSF’s other fantastic resources above, they also have a list of proprietary malware. It lists things, practices, and companies to avoid, and talks about the reasons why. Their addictions page is particularly good and relevant to my recent post on the problems of the attention economy.

The Surveillance Self-Defense site from the Electronic Frontier Foundation is a fantastic introduction into how corporate surveillance works and how to defend against it.

Use with a grain of salt:

Mozilla, the people behind Firefox, have a site called Privacy Not Included that rates products by how “creepy” they are. They focus more narrowly on privacy than the more expansive set of freedoms the FSF considers (privacy is one of a number of things the FSF looks at), and in some cases I would say Mozilla is too generous (eg, with the Amazon Kindle, a number of their data points are just incorrect.)

How To Join the Fediverse and Cast Off the Attention Economy

In a recent post, I wrote about how the attention economy in use at big social networks hurts you.

In this post, I’m going to suggest what to do about it.

Mastodon and the Fediverse

When you use email, you can send a message from an account at Google to one at Yahoo, Microsoft, or any of millions of businesses and organizations running their own mail server. Unlike, say, Facebook, email isn’t a single service, but rather a whole bunch of independent systems that can communicate (or federate) with each other.

The Fediverse is similar, and the most advanced Fediverse client is Mastodon.

Mastodon:

  • Lets you easily migrate your account from one Mastodon instance to another, similar to how you can migrate a phone number from one carrier to another
  • Lets you communicate with users across the Fediverse (other Mastodon instances, and those running other software too)
  • Supports very high-quality conversations through sensible moderation controls

It’s easy to get started! Head over to joinmastodon.org and click “Get Started”. Pick a community — don’t worry, this isn’t a hugely consequential decision, as you can always move or change later. You can browse activity from across the Fediverse, or just on your local community, so if you find a community with similar interests, it can be a neat way to find others to follow.

If you’re looking for more details, mastodon.help has a nice guide.

Defeating the Attention Economy

So, why does Mastodon make a difference?

First of all, you get to pick your host (and even software). With Twitter, you pretty much are using Twitter (yes, I know of things like Hootsuite, but for the vast majority of people, it’s twitter.com only). With Mastodon, you have choice. Pick the host that runs the software and has the kind of moderation you like.

Secondly, Mastodon is not for profit. There is no money to be made in keeping you on the site. Almost all Mastodon instances are ad-free. And Mastodon’s completely open protocols make it easy to go elsewhere if you like.

It’s Not Just Mastodon!

There are plenty of other programs in the Fediverse. And, this is really key, they all interact with each other. You can share photos in Pixelfed (sort of like a federated Instagram) and see them and comment in Mastodon! Some things to point out:

And there are many others.

This blog, for instance, runs WordPress and uses an ActivityPub connector; comments from the Fediverse integrate here.

Find me in the Fediverse

You can look me up: just type in @jgoerzen@floss.social in the search box of any Mastodon instance and click Follow. You can also follow this blog at @jgoerzen@changelog.complete.org.