In Microsoft Exchange, which role, introduced in the 2007 release, performs anti-spam filtering and applies messaging and security policies to messages?

In Microsoft Exchange, which role, introduced in the 2007 release, performs anti-spam filtering and applies messaging and security policies to messages?

• Hub Transport Server role
• Unified Messaging Server role
• Edge Transport Server role
• Mailbox Server role 

EXPLANATION

Deployed in a perimiter network, the Edge Transport Server role provides message protection and security. This protection is handled by various agents running on the Edge Transport
Server and act on email messages as they are processed.

Edge Transport Server Role – Edge Transport Server Roles sits at the edge of the network and it has to be installed on a standalone server. It performs a number of functions including Anti-spam and Anti-virus protection. The Edge Transport uses connection filtering, content filtering, recipient filtering, SenderID, sender and IP reputation to reduce the amount of Spam delivered to the end users inbox

SOURCE

https://technet.microsoft.com/en-us/library/mt616515(v=exchg.150).aspx