What about Tox or something like that? What about Jabber? By the way, bare e-mail is usually enough if you omit bloated signatures and quotations and just send

What about Tox or something like that? What about Jabber? By the way, bare e-mail is usually enough if you omit bloated signatures and quotations and just send short messages that way. There even is a Telegram clone which actually is an e-mail client.