Hello, I have same problem.
store = session.getStore(mailProvider);
store.connect(mailServer, mailUsername, mailPassword);
Folder [] sharedFolders = store.getSharedNamespaces();
Folder [] abcfolder = sharedFolders[0].list();
sharedFolders[0] is "Public Folders/". abcfolder is empty. However, it should contain lots of subfolders. I want to know the way to check shared public folders. Could anyone help?