You can enable drag and drop for your account to upload and send multiple files and folders. To begin:
1. Go to the Setup page
2. Click the menu item “Enable drag and drop” and follow the on-screen instructions
After you enable drag and drop you will see a large box with “Drag and drop files and folders here” when you send files (or upload files). Drag files and folders from your desktop or any file explorer window and drop them onto this box. Alternatively, you can copy files and folders to your clipboard and then click the “Paste” button.
Subfolders of folders are automatically added when you drag and drop a folder.
Alternatively you can use a FTP client to upload multiple files and folders.