使用 Yahoo 发送电子邮件时出现 SMTP 异常

Question

我有以下代码用于从我的应用程序发送电子邮件：

var config = DeserializeUserConfig(perfilAcesso.GetClientConfigPath() + "Encrypted");

using (SmtpClient client = new SmtpClient())
{
    client.Host = config.GetClientSMTP();
    client.EnableSsl = true;
    client.UseDefaultCredentials = false;
    client.Credentials = new System.Net.NetworkCredential(config.GetClientEmail(), config.GetClientPassword());

    using (MailMessage mail = new MailMessage())
    {
        mail.Sender = new MailAddress(config.GetClientEmail(), config.GetClientName());
        mail.From = new MailAddress(config.GetClientEmail(), config.GetClientCompany());
        mail.To.Add(new MailAddress("emailToReceive"));
        mail.Subject = "[PME] SOS - Equipamento Parado";
        mail.Body = "";

        client.Send(mail);
        MessageBox.Show("Email enviado com sucesso!");
   }
}

我设置了三个可能的 SMTP 主机供用户选择：Gmail ("smtp.gmail.com")、Outlook ("smtp.live.com") 和 Yahoo ("smtp.mail.yahoo.com")。

当我尝试使用 Yahoo 帐户发送电子邮件时，会引发此异常：

System.Net.Mail.SmtpException：邮箱不可用。服务器响应为：未采取请求的邮件操作：邮箱不可用。

我知道在使用 Gmail 和 Outlook 帐户发送电子邮件时，该方法非常有效，因为我尝试了多次。

我做错了什么？任何帮助将不胜感激！

Answer 1

第一步

client.Port = 587;

第 2 步

转到https://login.yahoo.com/account/security

第三步

启用允许使用不太安全的登录方式的应用

第 4 步：完整代码

using System;
using System.Net.Mail;

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {

            using (SmtpClient client = new SmtpClient())
            {
                client.Host = config.GetClientSMTP();
                client.EnableSsl = true;
                client.Port = 587;
                client.UseDefaultCredentials = false;
                client.Credentials = new System.Net.NetworkCredential(config.GetClientEmail(), config.GetClientPassword());

                using (MailMessage mail = new MailMessage())
                {
                    mail.Sender = new MailAddress(config.GetClientEmail(), config.GetClientName());
                    mail.From = new MailAddress(config.GetClientEmail(), config.GetClientCompany());
                    mail.To.Add(new MailAddress(config.emailToReceive));
                    mail.Subject = "Test 2";
                    mail.Body = "Test 2";
                    var isSend = false;
                    try
                    {
                        client.Send(mail);
                        isSend = true;
                    }
                    catch (Exception ex)
                    {
                        isSend = false;
                        Console.WriteLine(ex.Message);
                    }

                    Console.WriteLine(isSend ? "All Greeen" : "Bad Day");
                    Console.ReadLine();
                }
            }

        }
    }
}

如果您添加相同的电子邮件

 mail.To.Add(new MailAddress(config.emailToReceive));
mail.To.Add(new MailAddress(config.emailToReceive));

你会报错

错误的命令顺序。服务器响应为：5.5.0 Recipient already specified

如果你想重用 MailMessage

  mail.To.Clear();

Answer 2

您确定您的发件人/收件人地址正确吗？ From 和 sender 必须是您的 Yahoo 地址。

这是一个有效的示例：

public static void Main(string[] args)
{
using (SmtpClient client = new SmtpClient())
{
    client.Host = "smtp.mail.yahoo.com";
    client.EnableSsl = true;
    client.UseDefaultCredentials = false;
    client.Credentials = new System.Net.NetworkCredential("my-yahoo-login", "yahoo-password");

    using (MailMessage mail = new MailMessage())
    {
        // This works 
        mail.Sender = new MailAddress("my-email-address@yahoo.co.uk", "Tom Test");
        mail.From = new MailAddress("my-email-address@yahoo.co.uk", "Tom Test");
        mail.To.Add(new MailAddress("my-email-address@outlook.com"));
/* This does not
                mail.Sender = new MailAddress("my-email-address@outlook.com", "Tom Test");
                mail.From = new MailAddress("my-email-address@outlook.com", "Tom Test");
                mail.To.Add(new MailAddress("my-email-address@yahoo.co.uk"));
*/
            mail.Subject = "Test mail";
        mail.Body = "Test mail";

        client.Send(mail);
        Console.WriteLine("Mail sent");
    }
}
}

如果您将非雅虎地址放在发件人和发件人字段（注释代码）中，您将获得相同的异常。