Messenger

Delta Chat

надежные site.

Open source

Almost like Telegram or Whatsapp, but without tracking and centralized management.
No need to have your phone number.

Delta Chat does not have its own servers, instead it uses the largest and most distributed open messaging system: the existing network of e-mail servers.

Exchange messages with everyone whose email address you know, there is no need to install the DeltaChat application.
All you need is a standard email account.