# File app/mailsender/mail_sender.rb, line 55
        def add_text(text)
                @content << "--#{BOUNDARY}\n"
                @content << "Content-Type: text/plain; charset=iso-2022-jp\n"
                @content << "\n"
                @content << Kconv.kconv(text, Kconv::JIS) + "\n"
        end