一、提出问题现在,对于用户在 Web 页面上或电话中给出的 Email地址,我们越来越不敢肯定它是否真的有效。在今天这个垃圾邮件泛滥成灾的年代,人们完全有理由舍不得轻易透露Email 地址。另一方面,对于通过正规途径得到的邮件地址,当我们将它用于合法的目的时,也常常要为邮件地址是否有效而烦恼,用户可能有意或无意地写错地址,也可能由于长时间不访问而 I. Question Now, we are increasingly not sure if it is really valid for email addresses given by users on the Web page or on the phone. In today’s era of spam flooding, there is every reason to reluctant to disclose email addresses. On the other hand, for the e-mail address obtained through the formal route, when we use it for legal purposes, we often have to worry about whether the e-mail address is valid or not. The user may wrongly or wrongly address the e-mail address, Not to visit