c# - 使用 gmail 发送电子邮件。错误 : The server response was: 5. 5.1 需要身份验证

Question

对不起，我看到了很多关于这个问题的类似帖子，但没有找到解决我的问题的方法，所以我决定发布它。

我正在使用 ASP.NET c# 通过以下代码使用 gmail 以编程方式发送电子邮件。

 string EmailAddress = senderemail;
    MailMessage mailMessage = new MailMessage(EmailAddress, EmailAddress);
    mailMessage.Subject = "This is a test email";
    mailMessage.Body = "This is a test email. Please reply if you receive it.";

    SmtpClient smtpClient = new SmtpClient();
    smtpClient.DeliveryMethod = SmtpDeliveryMethod.Network;
    smtpClient.EnableSsl = true;
    smtpClient.Host = "smtp.gmail.com";
    smtpClient.Port = 587;

    smtpClient.Credentials = new System.Net.NetworkCredential()
    {
        UserName = EmailAddress,
        Password = senderpassword
    };
    smtpClient.UseDefaultCredentials = false;
    smtpClient.Send(mailMessage);

我和其他人一样收到这个错误

错误:

The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.5.1 Authentication Required. Learn more at.

已经在 GMAIL 中执行了以下 2 个操作。

-不太安全的应用程序:打开

-2步验证:关闭

我不关心这个 gmail 帐户是否安全。我不需要此帐户的任何安全性。我还应该做什么？

Answer 1

注册 Gmail 并转到 https://www.google.com/settings/security/lesssecureapps在哪里可以看到设置。访问安全性较低的应用

关闭(默认)==> 打开

添加这段代码后，

  MailMessage mail = new MailMessage("fromm@gmail.com", "toaddress@gmail.com");
                mail.Subject = "TestEmailImportant";
                mail.Body = "This mail is to test if this program is working";

                SmtpClient smtpClient = new SmtpClient("smtp.gmail.com", 587);

                smtpClient.Credentials = new System.Net.NetworkCredential()
                {
                    UserName = "XXXXXX@gmail.com",
                    Password = "YYYYYYYY"
                };

                smtpClient.EnableSsl = true;
                System.Net.ServicePointManager.ServerCertificateValidationCallback = delegate(object s,
                        System.Security.Cryptography.X509Certificates.X509Certificate certificate,
                        System.Security.Cryptography.X509Certificates.X509Chain chain,
                        System.Net.Security.SslPolicyErrors sslPolicyErrors)
                {
                    return true;
                };

                smtpClient.Send(mail);