how to memorize the position of windows in Nx, wich app is used ?

Every time I start a session, the window, for example Thunderbird if I click on it appears in the middle of my display, then I must move it if I want to use my web browser.

Thanks,
Phil

It is pretty irritating when that happens.

You could try this switch Menu> Preferences> Configuration ManagerOther than that, I think placement on the desktop is the realm of the application.

For example, Sylpheed, the email client, re-opens in the last position and dimensions. Other applications might have a switch to turn off/on previous setting.

I'm not familiar with Thunderbird, but I think the developers might be pretty proud and want it to be 'front and center', every time it is launched, unless of course there is a switch inside Thunderbird that 'remembers' last placement.