说明：  邮件系统在邮件夹中给每个邮件用户预先提供了4个邮件箱（收件箱、发件箱、草稿箱、垃圾箱）和地址本、邮件箱管理、自定义文件夹。
(E-mail system in the mail folder for each e-mail users to be provided in advance of the four e-mail boxes (Inbox, Outbox, Drafts, Trash) and address of the mail box management, custom folders.)