Its good you present where they have to start with.
Use the Start, Basics and launch pad links in the first mail.
Focus on fast track benefits and E365 benefits.
Along with this tell them to score at least 1500 versa points and send a mail to request for free tcredits and a GC for 2 USD to buy W3 Kit.
This works out well for me.
A lengthy mail will definitely make them skip or feel bored.