CREATE TABLE mail (
      id varchar(40)  PRIMARY KEY,
      contact_name varchar(255) ,
      contact_sex varchar(255) ,
      contact_id_card varchar(255) ,
      contact_phone varchar(255) ,
      case_number varchar(255) ,
      content text ,
      attachments longtext ,
      create_time timestamp,
      involved_dept_id varchar(255) ,
      involved_dept_name varchar(255) ,
      mail_state varchar(255) DEFAULT 'processing'
)