Since I got my first iPhone I ' ve always felt a little sluggish when it comes to receiving email . No more : The first time email arrived in Entourage on my Mac and on the iPhone at the same time - practically instantly - I realized what I ' ve been missing . Combined with the usability and terrific functionality of the 3 G network and iPhone 2.0 software and it 's just a little too much to describe . It just works , it works well , and it is usable to the point of not having to think about it -- the ultimate test for a usability engineer .
According to the above context, answer the following question.
Why might they require fast emailing on their iPhone ?


They send a lot of important emails .