The longest recorded document was a fax - Apparently.
In 1991, a team of researchers in the UK sent a fax from a computer to a fax machine that took 72 hours to transmit, covering a distance of over 1,400 miles. The document, a 200-page paper on the history of fax machines, was sent from a computer in Scotland to a fax machine in England. The transmission was made possible by the use of a special modem that could handle the vast amounts of data involved. The record was set by a team from the University of Strathclyde.