GetFolderList

// Create the folders filter with an account ID
DocuSignWeb.FoldersFilter filter = new DocuSignWeb.FoldersFilter();
filter.AccountId = _accountId;
// Now, call the method to get a list of the folders on the
// specified account
DocuSignWeb.AvailableFolders folders = _apiClient.GetFolderList(filter);
// Everyone will at least have the folders:
// Draft, Sent Items, Inbox and Deleted Items
// Print out some information about the returned folders
Console.WriteLine("The folders available on account {0} are:", _accountId);
foreach (DocuSignWeb.Folder folder in folders.Folders)
{
    Console.WriteLine("\t{0} owns folder {1}", folder.FolderOwner.UserName, folder.FolderTypeInfo.FolderName);
}