Naven
Glossary
Transport encryption
Encryption between your device and the server, and again between the server and the recipient — but not through the server itself.
This is what TLS does, and it is what the padlock in a browser's address bar means. It stops anybody on the network in between — a café's Wi-Fi, an internet provider, somebody with a packet sniffer — from reading what passes. Nearly every service on the modern web has it, and a service without it is broken rather than merely weak.
The difference from end-to-end encryption is the middle. Transport encryption protects the message in motion; the server still sees it on arrival. Which is fine, or not, depending entirely on what the server does with it.
Where Naven stands
Naven uses transport encryption everywhere and does not claim more than that. The server reads messages in order to screen them, which is the trade Naven makes and publishes.