Jkas 邮件发送

 String mail(String to,String subject,String content)

          String mail(String to,String subject,String content,String fromname)

               String mail(String to,String subject,String content,String fromname,String attachment1,String attachment2,...)//可以发送多个附件,附件为文件的绝对路径

           /*参数说明

              to:收件人邮箱地址

              subject:邮件主题

              content:邮件文本内容

              fromname:发件人名称

              attachment:附件文件绝对路径

            */