this account or directory type already exists and cannot be specific twice - Outlook 2007

I am using Exchange 2007 and Microsoft Outlook 2007.

I have already configured a email account. Now I want add another email account to my Outlook, to receive and send emails from that account.

When I go to tools/account settings, email, new, and I write the name, address of the new account, I receive the following message:

"Yo cannot add another account when Outlook is running. You must to do it in control panel/mail".

Once there, email accounts/email/new, and I receive the following message: "This account or directory type already exists and cannot be specified twice".