How to save all the read messages as a bulk to the computer without opening one by one?

Question

I have got almost 1000 messages in my mail box(almost 700MB). I need to save all the messages to the computer as a whole.

Answer 1

First, open a folder to hold them. Give it a name.

Then, in Yahoo Mail, Options, General Preferences, choose to display 50, for example, messages at a time.
Click the "check all" button
click "move to" button
move them to your new folder.

Why on earth do you want to save these? Read, answer or not, and get rid of them.