@Soft_Missy Your requirements may differ from mine of course. For me, @matrix is a natural fit. It allows to run your own instance if needed. It has E2EE built-in. There are multiple implementations for both server and client. Some people favor Signal, but that's a no-go for me due to centralization and only their blessed client being allowed to connect to this central service. For some communities, #RocketChat or #Mattermost are options. Don't know any other alternatives that would fit for me.
Server run by the main developers of the project It is not focused on any particular niche interest - everyone is welcome as long as you follow our code of conduct!