检查特定域中确实存在的电子邮件 [英] Check an email really exists in particular domain

问题描述

我正在使用一个模块来验证特定域中确实存在的电子邮件。

为此，我正在执行EHLO，MAIL From：和RCPT TO。我的代码验证了Gmail，但它不能在私人邮件ID中工作。



某些SMTP服务器将EHLO命令的响应发送为请求的操作已中止[7.2] 14306，请访问www.messagelabs.com/support以获取有关此错误消息的更多详细信息。



有些SMTP服务器响应EHLO命令为邮件被拒绝，因为你的IP在PBL中。请参阅http://www.spamhaus.org/pbl



以下是我的尝试。我的问题是

1.电子邮件验证（域名上的电子邮件）是否合法？

2.如果我验证批量电子邮件，我的IP黑名单会列出吗？



请帮我核实所有电子邮件。 />


我尝试了什么：



i跟着这个链接。以下是我的更改。

I am working in a module to verify an email really exists in particular domain.
For this i am executing EHLO,MAIL From: and RCPT TO. My code verifies gmail but its not working in private mail Ids.

Some SMTP servers sends response for EHLO command as "Requested action aborted [7.2] 14306, please visit www.messagelabs.com/support for more details about this error message."

Some SMTP servers respond for EHLO command as "mail rejected because your IP is in the PBL. See http://www.spamhaus.org/pbl"

Below is my try. My Question is
1. Email verification(Email exists on Domain) is Legal?
2. If i verify bulk emails, Will my IP black listed???

Please help me to verify all emails.

What I have tried:

i followed this link. Below is my change.

tcpSocket.Connect(hostEntry.HostName, 25);

                if (!CheckResponse(tcpSocket, 220))
                {
                    tcpSocket.Close();
                    return false;
                }

                //HELO server
                SendData(tcpSocket, string.Format("EHLO {0}\r\n", Dns.GetHostName()));
                if (!CheckResponse(tcpSocket, 250))
                {
                    tcpSocket.Close();
                    return false;
                }


                //Identify yourself
                //Servers may resolve your domain and check whether 
                //you are listed in BlackLists etc.
                MailFrom = "<" + strEmailAddress + ">";
                SendData(tcpSocket, string.Format("MAIL FROM: {0}\r\n", MailFrom));
                if (!CheckResponse(tcpSocket, 250))
                {
                    tcpSocket.Close();
                    return false;
                }

                SendData(tcpSocket, string.Format("RCPT TO: {0}\r\n", MailFrom));
                if (!CheckResponse(tcpSocket, 250))
                {
                    tcpSocket.Close();
                    return false;
                }

推荐答案

你不能。许多系统根本没有返回收据，有些只有在用户确认可以这样做时才会收到。

原因很简单：网络钓鱼者和垃圾邮件发送者想知道哪些是实时地址和（更重要的是）阅读电子邮件。为了防止这种情况，系统通常不会确认收到电子邮件 - 或之后发生的事情 - 除非用户明确允许这样做。这也是为什么大多数电子邮件系统默认不显示链接图像，以防止它们被用作阅读电子邮件指示器。



唯一可靠的知道方式如果一个真实的电子邮件地址是发送一封电子邮件，要求用户关注一个链接回系统 - 这就是大多数注册系统为此所做的事情。



抱歉 - 没办法做你想做的事。

You can't. Many systems do not return a receipt at all, some only when the user has confirmed it's ok to do so.
The reason is simple: phishers and spammers want to know which are "live addresses" and (more importantly) "read emails". To prevent that, systems generally do not acknowledge receipt of an email - or what happens to it after that - unless the user specifically permits this. This is also why most email systems do not display linked images by default, to prevent them being used as a "read email" indicator.

The only reliable way to know if an email address is real is to send an email which requires a user to follow a link back to your system - which is what most registrations systems do for just that reason.

Sorry - there is no way to do what you want.

这篇关于检查特定域中确实存在的电子邮件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！