C＃中的电子邮件存在检查

Question

I want to verify whether an e-mail is real or not. Some body told me I could do it with DNS check but I don't know how to do this.

Could somebody help me through this problem and I am developing with C#.

Thanks in advance.

Answer 1

I guess this code-project article gives you the information you want: Effective Email Address Validation

But even if you confirm that a domain is valid, it is still not guaranteed that the email address/recipient is valid. Eg "xyz@stackoverflow.com" -> the domain is valid, but "xyz" might not be a valid email address.

Answer 2

You can use DNS to determine if a domain is valid/resolving. That wouldn't necessarily mean that a given email address at that domain is valid. The only way to know that is to open an SMTP connection and try to send mail to that user.

Answer 3

从来没有这样做过，但这里似乎有一个非常好的C＃演练。

Answer 4

DNS check would imply parsing out the domain attached to the email address in question and making sure it resolves/exists.

Be aware that checking that the domain resolves/exists could take time since your application would need to wait for a response from whatever service you use to check if it exists.