OK, so what this purports to do is use your email server as chat platform. kinda intriguing, could have several use cases, don’t know what it does with existing email or how the chat looks like in e.g. thunderbird…
unfortunately, after installing it and being unsuccessful about having it login to my IMAP account (works fine with thunderbird), I’ve given up.
so, the “onboarding” is less than stellar and the desktop app is electron, which I hate; haven’t tried the android app.
edit: it works, the initial login process just takes super long; guess it’s trying different ports and stuff to be auto-magical. works fine for intra-server comms (accounts belonging to same domain), adding secondary device works (android, from f-droid). comms (encrypted) are stored in a separate IMAP folder that’s unreadable to “normal” mail clients, so it doesn’t disturb e.g. thunderbird. a fine array of customizations in the apps, will be testing it further.