Verb. When an e-mail client (web-based or otherwise) sticks legitimate e-mail in the "Junk E-Mail" folder for no damn good reason.
Also: Any time an e-mail program or web client filters out a legitimate e-mail through a spam-filter or any other form of electronic bullshit.
"My e-mail address hasn't been verified? Damn Hotmail must have junkfoldered that request. Fuck 'em."