[PanMan]

I'm a bit suprised: While Rainloop seems to the most modern opensource webmail client I could find (and I did do some research), from their github: _This is NOT a stable version of RainLoop Webmail. It's not recommended to use in production environment._ From my own testing there are certainly still a few bugs. Interesting they go with this for their primary webmail.

[tyingq]

If they are using the AGPL community version of Rainloop, that might also pull in some obligations they aren't meeting.

AGPL is pretty viral, even for a web app.