underneath the word `new' and left of the word `sort' is a small empty white box - tick it and all the emails will be highlighted - you can untick any individual ones you want to keep - then tick delete at the top.
I would think so.On Outlook Express,and Yahoo Mail, there is a facility to "select all"(which will highlight all messages".
Then click on delete and there you go.
I would imagine it should be the same on your main email account,and on hotmail too.
It's there,it's just a matter of finding it!
Good Luck.