Similar to AJoshi I was asked to migrate a Linux driven active postfix mail server to Exchange 2007. Working since more than a decade strictly in Unix environments I was curious how this would work.. So I went to buy this book and spent a nice weekend reading it. Sure enough I am impressed by the way the authors wrote this book. Clearly understandable bringing it to the real point. Having the book in front of me I easily managed to perform the migration. Today our users really appreciate the service they get from MS Exchange .... There is no way around this book if you are a newbie in the Exchange area !