created 2nd account but cant send mail


New Email
I created a new email account in outlook express but I have a problem. I tried to test the new account by sending and receiving a test mail. I can receive emails and I can reply to emails but when I go to create an email to send by default it is an email from my old account. How do I create an email in my new account.?

This is my first time creating a second account. Now I receive emails for my old account and my new account in the same inbox. Is this the way it's supposed to be? THanks.