Never heard of Cloud Phone, is it just sth like KaiOS based on chromium instead of firefox/gecko?
- WebRTC → is not needed by DeltaChat, for webxdc we went to great lengths to disable it.
- delta chat core (was recently renamed to chatmail-core) is written in rust, so it will be possible to adjust it to work in wasm, but will still take some work because of the non rust dependencies and the api differences between native and WebAPIs.
- You need TCP to speak SMTP and IMAP, but at least for chatmail we could host a proxy that translates web socket to those email protocols.
- we can add such a proxy to the chatmail relay, which means that every chatmail relay will have one eventually, though there is the question whether it would only allow to connect to the relay it is hosted at or to any email server, in the latter case it may get banned by bigger email providers for too much traffic.
For more details see the discussion in What would be needed for a Standalone web version without a server component?