A "nine of emails" is the collective noun for when you recieve an annoying number of emails (not necessarily nine) from the one person whining about a particular topic. It originated on a bulletin board called "toys in the attic" when a poster called "Coach" who is prone to exageration would claim "I have recieved not one, not two, but nine, repeat nine, emails" whenever he wanted to make people think he had alot of support for his bullshit opinions. From there it became the standard joke when someone would whine to the webmaster about some bullshit.
"how many many emails did you recieve? not one, not two but nine?"
"a nine of emails have flooded in from some whining asshole"