从 C# 程序发送邮件时访问被拒绝 | 程序发送邮件时访问被拒绝

本文介绍了从 C# 程序发送邮件时访问被拒绝的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我正在开发一个第三方插件以在名为 M-Files 的程序中运行.插件的目的是在 SMTP 服务器的帮助下发送邮件.我在 DevelMail.com 中创建了一个假的 SMTP 服务器，只是为了测试.从浏览器测试 SMTP 服务器有效，但是当我运行代码时，它给了我以下错误.

交易失败.服务器响应为:5.7.1 客户端主机被拒绝:访问被拒绝

以下是 SMTP 信息:
主机: smtp.develmail.com
SMTP 端口: 25
TLS/SSL 端口:465
STARTTLS 端口: 587
身份验证类型: LOGIN、CRAM-MD5

代码如下:

MailAddress adressFrom = new MailAddress("[email protected]", "M-Files Notification Add-on");MailAddress adressTo = new MailAddress("[email protected]");MailMessage message = new MailMessage(adressFrom, adressTo);message.Subject = "M-Files 插件正在运行";字符串 htmlString = @"<html><身体><p>尊敬的客户</p><p>这是使用写入元数据属性中的邮件地址发送给您的通知！.</p><p>此致，<br>-M-Files</br></p></身体></html>";message.Body = htmlString;SmtpClient 客户端 = 新 SmtpClient();client.Host = "smtp.develmail.com";客户端.端口 = 587;client.Credentials = new System.Net.NetworkCredential("myUserName", "myPassword");客户端.EnableSsl = true;客户端.发送(消息)；

解决方案

问题原因:

通常，使用 SMTP 的电子邮件发送选项遇到 Access denied因为应该有一个 sender email 需要允许远程访问.当 SMTP 请求从发件人电子邮件发送它检查是否允许远程访问.如果没有，那么你总是收到 Access denied 消息.

解决方案:

例如，假设您想使用 Gmail SMTP 发送电子邮件，在这种情况下您必须启用 Allow less secure apps: ON

如何设置

您可以简单地浏览此链接

代码片段:

 public static object SendMail(string fromEmail, string toEmail, string mailSubject, string mailBody, string senderName, string senderPass, string attacmmentLocationPath){尝试{MailMessage 邮件 = 新的 MailMessage();//在使用非gmail smtp之前必须更改SmtpClient SmtpServer = new SmtpClient("smtp.gmail.com");mail.From = new MailAddress(fromEmail);mail.To.Add(toEmail);mail.Subject = 邮件主题；邮件.正文 = 邮件正文；mail.IsBodyHtml = true;SmtpServer.Port = 587;SmtpServer.Credentials = new System.Net.NetworkCredential(senderName, senderPass);//输入你之前配置的credentailsSmtpServer.EnableSsl = true;SmtpServer.Send(邮件);返回真；}捕捉(例外前){返回前;}}

注意: 确保 fromEmail 和 (senderName, senderPass) 应该是与凭证相同的电子邮件.

希望这会有所帮助.

I'm developing a third-party add-on to run in a program called M-Files.The purpose of the add-on is to send a mail with the help of an SMTP server. I created a fake SMTP server in DevelMail.com just for testing.Testing the SMTP server from a browser works but when i run the code it gives me the following error.

Transaction failed. The server response was: 5.7.1 Client host rejected: Access denied

Here are the SMTP information:
Host: smtp.develmail.com
SMTP Port: 25
TLS/SSL Port: 465
STARTTLS Port : 587
Auth types: LOGIN, CRAM-MD5

Here is the code:

MailAddress adressFrom = new MailAddress("[email protected]", "M-Files Notification Add-on");
MailAddress adressTo = new MailAddress("[email protected]");
MailMessage message = new MailMessage(adressFrom, adressTo);

message.Subject = "M-Files Add-on running";
string htmlString = @"<html>
                    <body>
                    <p> Dear customer</p>
                    <p> This is a notification sent to you by using a mailadress written in a metadata property!.</p>
                    <p> Sincerely,<br>- M-Files</br></p>
                    </body>
                    </html>
                    ";
message.Body = htmlString;

SmtpClient client = new SmtpClient();
client.Host = "smtp.develmail.com";
client.Port = 587;
client.Credentials = new System.Net.NetworkCredential("myUserName", "myPassword");
client.EnableSsl = true;
client.Send(message);

解决方案

Reason for the Issue:

Solution:

For example let's say, you want to send email using Gmail SMTP in that case you do have to enable Allow less secure apps: ON

How To Set

You can simply browse this link Less secure app access and turn that to ON

See the screen shot

Code Snippet:

    public static object SendMail(string fromEmail, string toEmail, string mailSubject, string mailBody, string senderName, string senderPass, string attacmmentLocationPath)
    {
        try
        {
            MailMessage mail = new MailMessage();
            //Must be change before using other than gmail smtp
            SmtpClient SmtpServer = new SmtpClient("smtp.gmail.com");

            mail.From = new MailAddress(fromEmail);
            mail.To.Add(toEmail);
            mail.Subject = mailSubject;
            mail.Body = mailBody;
            mail.IsBodyHtml = true;

            SmtpServer.Port = 587;
            SmtpServer.Credentials = new System.Net.NetworkCredential(senderName, senderPass);//Enter the credentails from you have configured earlier
            SmtpServer.EnableSsl = true;

            SmtpServer.Send(mail);

            return true;
        }
        catch (Exception ex)
        {

            return ex;
        }
    }

Hope that would help.

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