Step 1: While writing an email, open the Attach File dialog by pressing Enter + F (dots 1, 2, 4).
Step 2: Navigate to the document you wish to attach.
Note: By default you begin in the Upload folder. To navigate to other folders, press Backspace to navigate up a folder in the folder structure.
Step 3: To attach a single file, press Enter with that file in focus on the device.
Step 4: To attach multiple files, press Space on each file you wish to attach, then press Enter to attach the selected files.