Free email newsletters with Mastodon! It’s now possible to subscribe to email updates for this blog, thanks to a new feature in Mastodon.

I’ve been a heavy user of Mastodon for a while. Recently, Mastodon has released a new version (4.6) that includes a particularly interesting change, in my opinion: the ability to subscribe to email updates for a user’s account, without requiring any Mastodon account, or any other kind of account on the Fediverse, for that matter. If you subscribe with your email address to a user’s account that has enabled this, then you’ll get an email update every time the user posts anything. That’s basically a free newsletter for everyone!

It seems that, by default, this capability is a bit limited in scope, and must be enabled in two steps:

• first, your Mastodon instance administrator must assign you a role which has the permission to enable this feature.
• second, as a Mastodon user, you need to go to your settings, and enable the email notification mechanism by default (under the preferences, then “Privacy and Reach”, then “Send posts via email”).

That’s awesome! Mastodon (as per the ActivityPub API requirements, as far as I know) already provides RSS feeds for each user, so you can follow a user either using your Fediverse client of choice¹, or an RSS feed, or by email now. No need for extra steps in IFTT or RSS-to-email systems!

I wish it were a bit more universally applicable, and that it would be possible for every user to do that, without the admin having to allow it on a per-user basis. But! I can easily imagine how it would become a moderation nightmare real fast. After all, a post on the Fediverse can be moderated a posteriori, i.e. after it’s been sent to the entire Fediverse; if the admin removed it, this will send a remove notification to all the servers that received it, and if they’re Well-Behaved™², they will remove it locally as well. But email doesn’t have that capability! Once an email has been sent, it will be received and it’s not possible to remove it from all the recipients’ inboxes after the fact. So, a user account could expose email subscriptions, then send crap to all its subscribers; this would occur a reputation cost for the sender email address, that would then affect the server reputation for all emails sent by the server… which would be super bad.

I’ve been already using Mastodon as a commenting system for this blog, using this technique I’d like to get more in details to later (and the reasoning why I can afford to do this). These days, I’m writing my posts in Silverbullet, a free and open-source self-hostable note-taking editor that’s also a fully programmable Lua³ environment. I’ve written small helper code to post a note on the Fediverse, with the post’s summary as well as a link to the post (using the Mastodon API). The code will then embed some metadata in the post’s source, so that the website knows how to fetch the replies to this post later; the replies are the comments.

So I already have a flow where I do post a note to the Fediverse. In addition to the new email notifications I’ve alluded to above, this instantaneously becomes a newsletter for the blog: each email will include the summary as well as the link to the full blog 🥳

If you want to subscribe by email to this blog, you can now do so by going to the blog’s public profile page here, enter your email address, and get updates whenever a post has been published!

That’s pretty sweet! Email newsletter for free! Yay for the Small Web!