ASP.NET C# - 从 Gmail/Yahoo 实时 SMTP 服务器发送电子邮件不工作

ASP.NET C# - Sending Email from Gmail/Yahoo Live SMTP Server not working

我正在努力尝试从 .NET 应用程序发送电子邮件。

我尝试了所有方法,包括创建一个新帐户 gmail 和 yahoo(更改了 yahoo 的主机),以及更改使用和不使用 mail.To 的端口,允许安全性较低的应用程序,我也尝试启用两步验证并为 gmail 提供应用程序密码,所有这些都失败了,并出现了同样的捕获错误:{"The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.1 Authentication required"}

这是我的代码:

 SmtpClient smtpClient = new SmtpClient();
        System.Net.NetworkCredential credentials = new System.Net.NetworkCredential("myemail@gmail.com", "pw");
        smtpClient.Credentials = credentials;
        smtpClient.UseDefaultCredentials = false;
        smtpClient.Port = 587;
        smtpClient.EnableSsl = true;
        smtpClient.Host = "smtp.gmail.com";
        smtpClient.DeliveryMethod = SmtpDeliveryMethod.Network;

        MailMessage mail = new MailMessage();
        mail.From = new MailAddress("myemail@gmail.com");
        mail.To.Add("myemail@gmail.com");
        mail.IsBodyHtml = true;
        mail.Subject = txtSubject.Text;
        mail.Body = txtBody.Text;
        try
        {
            smtpClient.Send(mail);
        }
        catch (Exception ex)
        {
            throw ex;
        }
        finally
        {
            if (mail != null)
            {
                mail.Dispose();
            }
        }

解决方案:由于人们将来可能会遇到问题,因此解决方案是删除以下代码行:smtpClient.UseDefaultCredentials = false;

smtpClient.UseDefaultCredentials = false;            
System.Net.NetworkCredential credentials = new System.Net.NetworkCredential("myemail@gmail.com", "pw");
smtpClient.Credentials = credentials;

按这样的顺序使用这些行。