How do i change the host and server on outlook express?

im trying to send a message to someone on craigslist and i need to change the host and server. how do i change it and what should i change it to?How do i change the host and server on outlook express?
If i didn't miss your point, you want to change default email account on outlook express(oe) so that the recipient see the email is from the specified account.

1. go to oe menu, tools, account, mail tab, add, go thru the procedure to set up the email account if you don't have 1 now.

2. just before you want to send the email, on the new message window, click From: box and choose the account you set up in 1. , if you have a lot of email to send through that account, go to the mail tab as stated in 1. and click the account line, click set as default button on the right.

3. if it's preferred, you can set up a new ID by going to oe menu, File, Identities, add new identities, once set up with the new account in it, you can specialize the new ID for correspondences send and receive someone on craiglist without mixing email with your original email account(s).

Hope this helps.