When using the desktop app, there are 3 situations the app communicate with online servers:
1. For WHOIS queries, the app communicates directly to the WHOIS servers, no middleman
2. For payment using Paypal's smart button. They might collect some data for fraud detection.
3. When checking for updates or form submissions. The app will send the only necessary information to our server. For updates, we need "platform" (i.e win32, darwin, etc.) and "version" (the current Domain Tool version, i.e "0.0.21"). For contact form submissions, we need "email", "message", and the "type" of form submission
Note that when submit a contact form, the server don't collect your IP. But as the nature of request, the server can read your IP.
P/s: This remind me to add the privacy section