Email error -The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.57 SMTP;

0
votes

I am trying to send email through my asp.net Application and it is throwing the error "The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.57 SMTP; Client was not authenticated to send anonymous mail during MAIL FROM [SG2PR0601CA0003.apcprd06.prod.outlook.com]"

       MailMessage message = new MailMessage();
        SmtpClient SmtpServer = new SmtpClient("smtp.live.com");
        message.From = new MailAddress("[email protected]");
        message.To.Add("[email protected]");
        message.Subject = "Test Email";
        message.Body = "Email Body";
        SmtpServer.Port = 587;
        SmtpServer.Credentials = new 
         System.Net.NetworkCredential("[email protected]", "xxxxxxxx");
        //SmtpServer.EnableSsl = true;
        SmtpServer.Timeout = 60000; // 60 seconds
        SmtpServer.Send(message);
2
c#asp.netemailoutlook
.Net version 4.5 and windows 10. – Mohan Singh
Possible duplicate of Cannot send email through Hotmail / live.com / outlook.com – wp78de

2 Answers

1
votes

1) Check the account credentials by logging in on the owa (www.outlook.com)
2) please check the link below as this will be the solution to your question
https://www.codeproject.com/Articles/700211/Csharp-SMTP-Configuration-for-Outlook-Com-SMTP-Hos

The 2 differences I already see are below
- SmtpServer.EnableSsl = true;
- new SmtpClient("smtp-mail.outlook.com")

In the article is also a cool section 'Use the App Password Instead of Your Outlook.Com Account Password'

1
votes

below code worked for me

    System.Net.Mail.AlternateView htmlView = null;
        string from = "[email protected]";
        using (MailMessage mail = new MailMessage(from, txtEmail.Text.Trim()))
        {
            mail.Subject = "Json File";
            htmlView = System.Net.Mail.AlternateView.CreateAlternateViewFromString("<html><body><div style='border-style:solid;border-width:5px;border-radius: 10px; padding-left: 10px;margin: 20px; font-size: 18px;'> <p style='font-family: Vladimir Script;font-weight: bold; color: #f7d722;font-size: 48px;'>Kindly find the Attachment.</p><hr><div width=40%;> <p  style='font-size: 20px;'>Thanks</div></body></html>", null, "text/html");
            mail.AlternateViews.Add(htmlView);
            mail.IsBodyHtml = true;
            System.Net.Mime.ContentType contentType = new System.Net.Mime.ContentType();
            contentType.MediaType = System.Net.Mime.MediaTypeNames.Application.Octet;
            contentType.Name = "New-Assign04.json";
            mail.Attachments.Add(new Attachment(Server.MapPath("~/App_Data/New-Assign04.json"), contentType));
            SmtpClient smtp = new SmtpClient();
            smtp.Host = "smtp-mail.outlook.com";
            smtp.EnableSsl = true;
            NetworkCredential networkCredential = new NetworkCredential("[email protected]", "xxxxxxxx");   // username and password
            smtp.UseDefaultCredentials = true;
            smtp.Credentials = networkCredential;
            smtp.Port = 587;
            smtp.Send(mail);
        }