一、什么是目录服务?在现实生活中电话是常用的通讯工具,我们可以通过电话号码簿或者114查号台来查询受话方的电话号码。而在Internet 上,最常见的通讯服务是电子邮件,如果上网用户希望通过电子邮件与其他用户联系,那么如何得到对方的电子信箱地址就成了当务之急。在相识的同学、朋友之间交换电子信箱地址的 First, what is a directory service? In real life, the telephone is a commonly used means of communication, and we can check the phone number of the called party through the phone book or the 114 search station. In the Internet, the most common communication service is e-mail, if Internet users want to contact other users by e-mail, then how to get each other’s e-mail address has become imperative. In the acquaintance of classmates and friends to exchange e-mail address