I'm using client.FileExists and it always seems to return false even though the file exists.
Does that function take the whole folder path, the site URL + path or just the file name?
You can use just the "filename" - FTP server will use the current folder (you can change the current folder using FTP.ChangeFolder method), or the path relative to the current folder e.g. "./folder/file.txt" or full absolute path e.g. "/folder/file.txt".