C# yandex mail send error 5.5.4 Error: send AUTH command first

Question

I try to send mail using C# and yandex, but I get an error:

Error 5.5.4 Error: send AUTH command first

Here is my code. I try w

Answer 1

I solve this problem my changing the SMTP host from smtp.yandex.com to smtp.yandex.ru and i was using port 25. Works for me perfectly. Here is the code:

EmailCredentials credentials = new EmailCredentials();
    credentials.Domain = "domain.com";
    credentials.SMTPUser = "webmail@domain.com";
    credentials.SMTPPassword = "pass";
    int SmtpPort = 25;
    string SmtpServer = "smtp.yandex.ru";

    MailMessage EmailMsg = new MailMessage();
    EmailMsg.From = new MailAddress("webmail@domain.com", "Domain");
    EmailMsg.To.Add(new MailAddress("info@domain.mk", "info@domain.mk"));
    EmailMsg.ReplyToList.Add("info@domain.com");

    EmailMsg.Subject = "Welcome";

    EmailMsg.Body = "HTML body code";

    EmailMsg.IsBodyHtml = true;
    EmailMsg.Priority = MailPriority.Normal;

    System.Net.Mail.SmtpClient SMTP = new System.Net.Mail.SmtpClient();
    SMTP.Host = SmtpServer;
    SMTP.Port = SmtpPort;
    SMTP.EnableSsl = true;
    SMTP.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;
    SMTP.UseDefaultCredentials = false;
    SMTP.Credentials = new System.Net.NetworkCredential(credentials.SMTPUser, credentials.SMTPPassword);

    SMTP.Send(EmailMsg);