The major thrusts of e-mail hygiene are spam management and security from viruses and other e-mail threats, including hacker attacks.
"Practicing good e-mail hygiene," Computing Canada, September 5, 2003
"It has nothing to do with the year 2000," he said. "Good e-mail hygiene says you don't open attachments from somebody you don't know."
Christie Appelhanz, "Y2K not only concern in new year," Topeka Capital-Journal, December 25, 1999
Kevin Jonah, "Catch viruses," Government Computer News, June 1, 1999