The phrase, "Is best mail for you!" is partly responsible for the unique voice of Homestar from the website homestarrunner.com. It was originally a phrase spoken by Homestar creator Matt Chapman as a prank when he was altering the system sounds of his brother Mike's computer. He initended the sound bites to sound like a young Japanese girl. Homestar's voice resulted.
Matt: "...it was supposed to sound like this little Japanese girl so when he got mail it's like, 'is best mail for you!'".