Yes, sorry, my post was confusing.
The actual questions to @steve were along the lines of:
- is this an online app or an offline app?
if an online app …
- can you configure which server is used?
- which server is used by default?
- what other servers are available to choose?
- can you run a private server yourself? e.g. on local network or e.g. on the phone itself or e.g. on the internet but restricted to your use
Without getting too bogged down in my stated opinion (about copying your communications to Google) … part of the concern is that if you take a bunch of text in a foreign language (that you don’t understand) and drop it into Google Translate then you may be identifying yourself from that text, regardless of login credentials, VPN, IP address, … (in addition to leaking other personal information).
Your actual name could be in that foreign language text. Someone else’s actual name could be in there. Granted that you could censor actual names in some cases. (In other cases, not e.g. I’m guessing most of us would not recognise our own name if appearing in Chinese text.)
Sufficient PII may be in that foreign language text so that, combined with information from elsewhere on the internet that is accessed by the Google Snout ⚇, which pokes its nose in everywhere, you may be fully identified even without your actual name appearing.
By doing this, regardless of your own personal opinion, you may be letting the other party down. That is, if this is an email or other direct messaging from someone else in a foreign language, you should really get agreement from the other party before using an online translator. If this is text published on a web site but the page on the web site has restricted access then the same could apply.