A person, usually but not always female, who uses the lowly and once-derided exclamation point indiscriminately, frequently in e-mails that begin "Hello!" or some such inanity.
He silently categorized the candidate as an Exclamista, having read her ingenious cover letter -- which, like many, began "Dear Sir!"; he would hire this hottie regardless, resigning himself to years of e-mails beginning "Thank you for the update!".