Configuring Exchange 2007 Hub Transport role to receive Internet mail
The MSExchangeTeam.com has published an entry about how we can set the Hub transport to receive and send e-mails to internet. Another interesting point is the possibility to add anti-spam features at hub transport using a built-in script located under scripts folders.
And we can see a new tab that doesn't exist in the Beta2 to define the anonymous permissions.
Read more at source: http://msexchangeteam.com/archive/2006/11/17/431555.aspx