Kontact has several command line arguments that can be used for certain actions.
First of all, Kontact supports command line arguments that all KF5/Qt™ applications support, see the man pages qt5options and kf5options.
Kontact also supports several command line arguments specific to it.
To get a list of available Kontact modules, you can type:
% kontact --list
Then, to start Kontact with a module active, type:
% kontact --module
moduleName is one of the modules obtained using the
To start Kontact in iconified mode, you can type:
% kontact --iconify
 Iconified mode is also called minimized; it is when the application window is hidden and the application is available only in the taskbar.