You did not provide the necessary internal mail server and accepted authoritative domain information required on this page of the E-Mail Policy Wizard.

On the Internal Mail Server Configuration page, do the following:

• Under Internal mail servers, click Add and type the computer name and IP address of your internal SMTP server (for example, mail.internal.contoso.com). Do this for each of your internal SMTP servers.
  
  

  Note:
  If you are using a Microsoft Exchange messaging organization, type the computer name and IP address of the appropriate Hub Transport server.

• Under Accepted authoritative domains, click Add and type the SMTP domain names or IP addresses from which your internal SMTP servers accept mail messages (for example, mailsrv.internal.contoso.com). Do this for each internal SMTP server.