# File lib/mail/attachments_list.rb, line 94
    def set_mime_type(filename)
      # Have to do this because MIME::Types is not Ruby 1.9 safe yet
      if RUBY_VERSION >= '1.9'
        new_file = String.new(filename).force_encoding(Encoding::BINARY)
        ext = new_file.split('.'.force_encoding(Encoding::BINARY)).last
        filename = "file.#{ext}".force_encoding('US-ASCII')
      end
      @mime_type = MIME::Types.type_for(filename).first
    end