问候(good moring),名号(i am jack from Four Stars Computers),目的(讲述为何来),
I am talking to you from features,advantages and benefits.
First,,features. ....
Second,,advantags....
(compared to your old XXX,this one works ...)
Third,benefits....
(Some of you may complain about .... But this one ...)
Having said this much, i highly suggest that you think about it and don't miss the chance to ...