How do I save my emails into my usb, but definitely not one by by one, since that takes too much time. A system similar to Gmail saving the draft automatically as I am composing my email every few (I don't know how long). Also how to do the past emails.

I can see why you don't want to do all your emails one at a time. It could get tedious. You do not say which email system you're using. IF YOU'RE USING OUTLOOK or OUTLOOK EXPRESS.... it's easy, but slow. Open the folder to view your list of emails, then click and select the emails you want to save (click on one and Control-A selects all in the folder), then drag them into a folder on your hard drive or USB drive. Each email will become a file with a name taken from the email subject. It really is time-consuming. Probably better to drag to hard drive first and then copy to USB if you're doing more than a few.