Even so, much like how users of one email service such as Gmail can still send emails to users of another service such as Outlook, users may still view content and interact with users on any other instance in the fediverse
which implicitly says email is not considered part of the fediverse by comparing the two.
https://en.wikipedia.org/wiki/Fediverse
According to Wikipedia, ActivityPub is the “most widely used” protocol, but not the “only” protocol. Still not sure if email would qualify though.
The others listed are bluesky, nostra and farcast. I suppose we could count protocols that nobody uses…
They literally use email as an example in the wiki page, lol
The mention of email is
which implicitly says email is not considered part of the fediverse by comparing the two.