无法使用来自 GoDaddy 配置的 Office 365 帐户的 C# 代码发送电子邮件

Question

我已从 GoDaddy 购买了“Office 365 Email Essentials”计划来发送电子邮件。我可以在我的 Outlook 邮箱中发送和接收这些电子邮件，但不能通过 C# 代码以编程方式发送。我一直收到错误“

SMTP 服务器需要安全连接或客户端未通过身份验证。服务器响应为：5.7.57 SMTP；在 MAIL FROM [BMXPR01CA0092.INDPRD01.PROD.OUTLOOK.COM] 期间，客户端未通过身份验证发送匿名邮件”

MailMessage msg = new MailMessage();
        msg.To.Add(new MailAddress("xxx@gmail.com", "xxx"));
        msg.From = new MailAddress("xxx@mydomain.com", "Admin");
        msg.Subject = "This is a Test Mail";
        msg.Body = "This is a test message using Exchange OnLine";
        msg.IsBodyHtml = true;

        SmtpClient client = new SmtpClient();
        client.UseDefaultCredentials = false;
        client.Credentials = new NetworkCredential("xxx@mydomain.com", "mypassword","mydomain.com");
        client.Port = 587;
        client.Host = "smtp.office365.com";
        client.DeliveryMethod = SmtpDeliveryMethod.Network;
        client.EnableSsl = true;
        //Send the msg
        try
        {
            client.Send(msg);
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }

这是配置文件中的 mailsettings 条目 -

<mailSettings>
<smtp from="xxx@mydomain.com">
  <network host="smtp.office365.com" port="587" />
</smtp>
</mailSettings>

我在 Outlook 中看到的设置是 -

服务器名称：smtp.office365.com 端口：587 加密方式：STARTTLS

或者，我也尝试使用用户 ID 代替网络凭据中的实际电子邮件地址，但这也不起作用。

我还尝试在 GoDaddy 中使用 MX Txt 记录，即服务器“relay-hosting.secureserver.net”和端口 #25，但没有成功。

我还根据链接http://edudotnet.blogspot.com/2014/02/smtp-microsoft-office-365-net-smtp.html更改了“邮箱委托”中的设置，但这也无济于事。

请帮助我在这些步骤中缺少什么。

Answer 1

在花了几个小时之后，我发现godaddy配置的office 365邮件ID的smtp主机是“ smtpout.secureserver.net ”。

还将客户端编程为关闭连接，如下所示：

SmtpClient client = new SmtpClient {

   Host = "smtpout.secureserver.net",

   Credentials = new NetworkCredential("USERNAME@DOMAIN.COM", "YOURPWD"),

   Port = 587,

   EnableSsl = true,

   Timeout = 10000

};

这些更新后，它会工作！！！享受！

示例控制台应用程序代码！

static void Main(string[] args)
        {
            try
            {
                ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

                string userId = "username@domainname.com";
                string _pwd = "mypassword";
                var toAddress = "touseremailaddress";
                SmtpClient client = new SmtpClient
                {
                    Host = "smtpout.secureserver.net",
                    Credentials = new NetworkCredential(userId, _pwd),
                    Port = 587,
                    EnableSsl = true
                };
               
                var Msg = new MailMessage();
                Msg.From = new MailAddress(userId);
                Msg.To.Add(new MailAddress(toAddress.ToString()));
                Msg.Subject = "TEST EMAIL";
                Msg.Body = "Hello world";

                Console.WriteLine("start to send email over SSL...");
                client.Send(Msg);
                Console.WriteLine("email was sent successfully!");
                Console.ReadLine();
            }
            catch (Exception ep)
            {
                Console.WriteLine("failed to send email with the following error:");
                Console.WriteLine(ep.Message);
                Console.ReadLine();
            }
        }