Mac Mail Setup with OS X Lion
Open System Preferences. Choose Mail, Contacts & Calendars from the Internet & Wireless section.
Highlight Add Account on the left and choose Microsoft Exchange on the right.
Fill in your name, email address and password as necessary and click Continue.
If AutoDiscover is configured correctly for your domain, no further input will be necessary and your account Summary will be displayed. Click continue.
(If the wizard is not able to determine it automatically, and you are prompted for the server name, the server is mail.webville.net)
Confirm that Mail, contacts and Calendars are selected and click Add Account.
You will return to the Mail, Contacts & Calendars main dialog with your new account displayed.
Close System Preferences and start the Mac Mail App. Give it time to start downloading all the messages in your mailbox.
Optionally, if you have trouble or want to verify the detailed settings, from within the Mail app, click the Mail menu, choose Preferences and compare your settings to the screen shots below.