Proton will buy it, so proton will read all your notes (we remember proton’s “E2EE”)

The main Linux myth is: “Linux is OS”

Other alternatives: Status(https://status.app), speek!(https://speek.network), Briar(https://briarproject.org), Cwtch(https://cwtch.im) and Tox(https://tox.chat/index.html).

Obsidian and logseq

Maybe kMail(very beautiful) or disroot(more about freedom and not very beautiful). Both open source.

StartMail, Soverin, Disroot, Infomaniak Kmail, Mailfence, Mailbox.org, Kolab Now And Posteo

Use any matrix client unstead.