Install and manage smtp

Hello,

I've a domain with two windows server 2008 which are dc.

In my domain I've mainly windows 7 x64 and windows xp.  My boss asked me whether it would be possible to control all the traffic of each pc controlling the NIC of  each PC.

This is why I'd like to install the SMTP service for each pc.

Can anybody tell me how I could create a GPO for installing and managing the SMTP for all the pcs of the domain? (I think smpt is not installed by default on windows 7)

Thanks in advance.

Regards.