Available Web Server (IIS) Role Services in IIS 7.5
Handy post of features and what versions / modules are available on Windows.
http://technet.microsoft.com/en-us/library/cc753473.aspx
SMTP Email on Windows Server 2008 R2 configuration
http://technet.microsoft.com/en-us/library/cc753146(WS.10).aspx
Steve Schofield
Microsoft MVP - IIS