This does not bode well. Matrix is honestly not good, as someone who has tried to use it. It's slow, janky, often unstable, and poorly standardized.
My suggestion: https://threema.com/en/products/work (hosted) or https://zulip.com/ (OSS self-hosted).
While I don't doubt your experience, I've been running Conduit[0] for a while now to great success (a lot simpler to configure than Synapse).
I don't think it's a fact that Matrix is not good. For MS Teams? It's pretty close to a fact.
When did you try it? Both Matrix the protocol and implementations like Element X have improved immeasurably over the last year or so.
Personally I've found Matrix significantly more user friendly than Threema work. Zulip I haven't used in anger so I can't comment on that but I've seen a few places that even open source they charge per user for things like notifications. Not ideal IMHO. There should be an option to replace notifications with a separate service.
It's hard to find a decent service that ticks all the boxes but I do sincerely hope that the EU can support Matrix to bring it up to the standard that we all deserve.
Threema: proprietary, outside EU
Zulip: lacks encryption, interoperability
> Mobile notifications for organizations with up to 10 users
Why does the self-hosted edition have this restriction? If the software is truly OSS, the limit could be trivially patched. But this kind of restriction just does not inspire much confidence in the project to be honest.
Can you be more specific about your criticisms? I have gripes about Matrix, but your assessment doesn't match my experience.
Sounds like something Europe would love.
I've been running a Matrix homeserver for a couple of years now and I've never had any issues with it. Not saying Matrix is perfect, but it is not as bad as you are making it out to be either.