That was the first thing I tried, but to no effect

Hello,
I have used Opera's built-in mail client on Windows, and when I left the company I took with me Profiles folder. In it, there is n2xdb9mv.default/Mail/ sub-folder, and within a "Local Folders" sub-folder. Every mail folder I made is there. How can I import them in Opera, or can I read them with some other mail client?

I have tried an Import feature of Opera, but it asks for opera.ini file, which I don't have.