Make the first screen count. If all I see is a repurposed paper press release, with the contact information and little else on the first screen, it's a waste of time. Put useful information high up. Give me a reason to scroll down. Unless I have specifically asked for an attachment, don't send one.
Attachments are bandwidth hogs.
That's particularly a problem for travelers. It isn't fun to be sitting in a hotel in Singapore, waiting for an hour while some mega-hog PowerPoint file drizzles into my inbox. File attachments have become the preferred virus carrier for the jerks who like to pollute people's computers. They're unnecessary, except in the rarest of cases. Plain text will almost always do everything you needed.