The local computer is running the Edge Transport role
Topic Last Modified: 2006-06-06
Microsoft® Exchange Server 2007 setup cannot continue because its attempt to install an Exchange 2007 role found the Gateway Server role already installed on this server.
Exchange 2007 setup cannot install other server roles on a server that has the Microsoft Exchange Gateway Server role installed.
The Microsoft Exchange Gateway Server role is deployed in your organization's perimeter network, handles all Internet-facing mail flow, and provides the encryption and decryption of messages sent between trusted Microsoft Exchange organizations in addition to protection against spam.
To resolve this issue, install the other Microsoft Exchange 2007 roles to a computer that does not have the Gateway Server role installed.