How to empty folders when I run out of room

To do this, look on the left side of your
screen at the bottom there is a scroll bar. Scroll over to the right and
check inbox, trash and junk. Beside each folder there is the world "empty".
Clicking on "empty" will remove the contents of that box. If there are items
you want to keep, DON'T click empty. Open the box and put a check beside the
e-mails you don't want, then hit delete.