Notebook ML provides a general purpose notebook to do as you see fit with. It is basically a jot pad you can use for any information you wish to keep. It may also be used as a temporary storage location for cutting and pasting information between various system windows; which for whatever reason cannot share the screen at the same time. Generally, people tend to keep large amounts of old mail online because there are items in the messages they need to remember or act on. Usually this information is only a few words; not the entire message. The notebook provides a place to put that information so that the messages may then be deleted (and also so you don't have to apply a filter to the entire mailbox to find it again). This is only one potential use. Other uses are limited only by your needs and imagination. There are two selections within the File menu. menu. Save and Close Window. Both will save the current contents of your notebook. It would be wise to select Save after new information is entered so that it will be saved in the event of a future system failure or abnormal program exit; however there is an automatic timer which will save it at preset intervals. The length of time between saves may be set from the Main Window->Option->Option Settings dialog.