I just found this great post on a forum : Linux Mint Forums
Here are the steps to synchronize your box files on Linux with the dolphin file manager :
- Open Dolphin, click on network
- Click on "Add Network Folder"
- Check the box "Webolder (webdav)", click next
- Fill in the form :
- Name : whatever you want
- User : the email address you use to log in box webapps
- Server : dav.box.com
- Port : 443
- Folder : /dav
- check BOTH check box "Create an icon..." and "Use encryption"
- Click on "Save and Connect"
- Enter your password
- Optionally right click on the newly created folder and add it to places
Enjoy !