如何验证现有的电子邮件地址。

how do i validate Existing E-Mail Address.

在一个登记制度，当用户输入检查，如果电子邮件地址是现有的或一个电子邮件地址没有Ymail / Gmail的。

in a Registration system, when a user enter a Email address it checks if the Email address is existing or not in Ymail/Gmail.

我已经有一个正在运行的域（实践）。

i already have a running domain(for Practice).

您有我的问候。

推荐答案

SMTP提供VRFY和EXPN动词来检查，如果一个帐户或邮件列表存在。然而，大多数服务器管理员禁用来自他们的邮件配置，以prevent黑客这些动词者利用用户列表。 Gmail和雅虎都表示，已经禁止VRFY

SMTP provides VRFY and EXPN verbs to check if an account or mailing list exists. However, most server admins disable these verbs from their mail configuration to prevent hackers from exploiting user lists. Gmail and Yahoo are said to have VRFY disabled.

您可以尝试为这些服务器的另一种选择是通过电子邮件发送给用户一个链接，以确认他们的电子邮件地址。当然，它并不像性感实时电子邮件验证，但它是更安全的各方。

Another option you can try for these servers is emailing the user with a link to confirm their email address. Granted, it is not as sexy as realtime email verification, but it is more secure for all parties.