vnt_reader.rb

class VntReader
  def initialize(file)
    @file=file
  end

  def body
    @file.each_line.select{|l|l.match /\ABODY/}.first.chomp
  end

  def content
    body.match(/\ABODY.*QUOTED-PRINTABLE:(.*)/)[1]
  end

  def decoded_content
    content.unpack('M').first
  end
end

p Dir.glob('*.vnt').map{|filename| File.open(filename,'r'){|f| VntReader.new(f).decoded_content }}