Change email address Network Admin emails come from


I am wondering what I am missing when trying to change the email address that Network admin emails come from!

Under Network Settings, the email address is (domain blanked). Yet the emails all come from They also appear as from "Wordpress" as the email sender... is it possible to change this so they appear as from my site name? I find most of the users automatically delete things from Wordpress as they dont know what it is, then tell me they haven't got any emails from their blog.