Usually I mixdown the tracks I want to share as .wav file(s). Then send those files. The receiver then imports the .wav audio files into a project on their machine. I usually send a file for each separate track and one complete project file mixdowned from the main stereo out.
I have also performed a mixdown to .mp3 and shared these too. It just depend on why I am sharing. For editing purposes it is .wav files. For listening purposes it is .mp3.
I never had any luck copying and sending an actual project .cpr file and all other project related files. For me, sharing like this never worked out because both computers need to be set up exactly the same for the project to open and work properly.
Regards. 