Of course, and we even recommend you do so !
CannaJob is trying to bring more humanity to the company-freelancer relationship. To the extent that it’s possible, we find it important that you discuss your skills and the mission with the client, as well as show your professionalism and motivation.
You can thus meet them, Skype them, have a phone call together.
However, to remain secure, do keep your written conversations on the platform so as to keep a central archive of the mission details.