Click on Tools

Click on Accounts

Click on Add and them Email

Fill up your complete name. Then "Next"

Fill up here with you email address.

Now fill up with the POP3 and SMTP servers names. Both of them are mail dot your domain name without www.
For example: mail.valim.net

The accounts name is your email address. Fill up your password too and select "Remember password"

Almost ready! Click on Finish.

One more step yet. Your mail server is your account name for instance. Click on Properties.

You may change (or not) your account name for another more friendly one. For example, Valim.Net (to say to you this is your valim.net account).

Click on "My server requires authentication"

That's it! Your email account is ready now and you can use it with your Outlook Express.