How We Sent a Man to the Moon Without E-mail and Why It Matters Today

They used interoffice memos.

Take a look at this citation list for "Lunar Impact: The NASA History of Project Ranger" - http://books.google.com/books?id=UewO7htzSv4C&pg=PA386&lpg=P... and see just how many are "interoffice memo from X to Y".

They also had voice-operated memo writers, also known as secretaries, typists, or stenographers.