Click on Tools > E-mail Accounts

Select "Add a new email account", and click Next

You will see a screen similar to this:

Enter the following info:

Your Name: Enter your name
Email Address: user@yourdomain.com
User Name: user@yourdomain.com (must be your full email address)
Password: The password for the email account 
Incoming Mail Server (POP3): mail.yourdomain.com
Outgoing Mail Server (SMTP): mail.yourdomain.com
Make sure that the box for Log on using secure password authentication (SPA) is NOT checked
Should look similar to this:

Select the "More Settings"... button on the bottom right.

Check the "My outgoing server requires authentication" box

Click on the OK button and you will be back at this screen:

Click the "Test Account Settings" button. This will make sure the account works.

Now just click Next:

And Finish.

Note that some changes

require closing outlook and reopening it before they take effect