远离Gmail SMTP服务器，还是还有其他选择？

Question

由于Google停止较少安全的应用程序功能功能更难更难使用其SMTP服务器发送电子邮件，我已经迁移到另一个提供商。

现在，我要获得STMP服务器需要安全的连接，否则客户端未经身份验证。服务器响应是：需要身份验证5.7.0。

该代码与Gmail的Out Out SMTP运行良好，但我的新服务器正在抱怨。我尝试了几种代码变化，结果是相同的。

private void SendEmail()
{
  MailMessage message = new MailMessage();
  SmtpClient smtpClient = new SmtpClient("smtp-relay.sendinblue.com");
  message.From = new MailAddress("[email protected]");
  message.To.Add("[email protected]");
  message.Subject = "NEW LICENCE REQUEST FROM " + ((User) this.Session["User"]).Name;
  message.Body = "LICENCE DEATIL" + Environment.NewLine + "SELLER = " + ((User) this.Session["User"]).Name + Environment.NewLine + "ID = " + this.TextBox__id.Text + Environment.NewLine + "NAME = " + this.TextBox__register_nam.Text + Environment.NewLine + "ADDRESS = " + this.TextBox__address.Text + Environment.NewLine + "LIC = " + this.TextBox__licence.Text + Environment.NewLine + "PDA = " + this.TextBox__pda.Text + Environment.NewLine + "CONTACT = " + this.TextBox__contact.Text + Environment.NewLine + "PHONE = " + this.TextBox__phone.Text + Environment.NewLine + "EMAIL = " + this.TextBox__email.Text + Environment.NewLine + "EXP = " + this.Calendar.SelectedDate.ToShortDateString() + Environment.NewLine + "AD SCREEN = " + this.CheckBox__AdScreen.Checked.ToString() + Environment.NewLine + "Biometrics = " + this.CheckBox__Biometrics.Checked.ToString() + Environment.NewLine + "Debit = " + this.CheckBox__Debit.Checked.ToString() + Environment.NewLine + "Draft = " + this.CheckBox__DraftControl.Checked.ToString() + Environment.NewLine + "KitchenScreen = " + this.CheckBox__KitchenScreen.Checked.ToString() + Environment.NewLine + "LiquorControl = " + this.CheckBox__LiquorControl.Checked.ToString() + Environment.NewLine + "WinAuthorize = " + this.CheckBox__WinAuthorize.Checked.ToString() + Environment.NewLine + "Lite = " + this.CheckBox__Lite.Checked.ToString() + Environment.NewLine + "CashNoBill = " + this.CheckBox__DisableCashNoBill.Checked.ToString();
  smtpClient.Port = 587;
  smtpClient.Credentials = (ICredentialsByHost) new NetworkCredential("[email protected]", "XSnfc213213216");
  smtpClient.EnableSsl = true;
  smtpClient.Send(message);
}

出于隐私原因，凭证已更改。

Answer 1

如果您想留在Gmail SMTP中，您有一些选择。无论哪种方式，您的错误

5.7.0所需的身份验证。

意味着您需要进行身份验证才能使用该SMTP服务器。这意味着您需要配置OAuth2。与Google SMTP服务器一起使用的Simlar to XoAuth版本的Simlar。我将检查该新服务器的文档，它应该告诉您如何配置授权。

的Google SMTP选项

在删除较不安全的应用程序功能之后，下面

是使用Google SMPT服务器的两种方法。 XOAuth2

以下代码显示了如何将XOAuth2与Google SMTP服务器一起使用。它要求您在Google Cloud Cloud Console 上创建安装的应用程序凭证。

using Google.Apis.Auth.OAuth2;
using Google.Apis.Util.Store;
using MailKit.Net.Smtp;
using MailKit.Security;
using MimeKit;


var path = @"C:\YouTube\dev\credentials.json";
var scopes = new[] { "https://mail.google.com/" };
var userName = "test2";

var credential = GoogleWebAuthorizationBroker.AuthorizeAsync(GoogleClientSecrets.FromFile(path).Secrets,
    scopes,
    userName,
    CancellationToken.None,
    new FileDataStore(Directory.GetCurrentDirectory(), true)).Result;

credential.GetAccessTokenForRequestAsync();

var message = new EmailMessage()
{
    From = "[email protected]",
    To = "[email protected]",
    MessageText = "test",
    Subject = "test"
};

try
{
    using (var client = new SmtpClient())
    {
        client.Connect("smtp.gmail.com", 465, true);
        
        var oauth2 = new SaslMechanismOAuth2 ("[email protected]", credential.Token.AccessToken);
        await client.AuthenticateAsync (oauth2, CancellationToken.None);
        
        client.Send(message.GetMessage());
        client.Disconnect(true);
    }

   
}
catch (Exception ex)
{
    int i = 1;  // throws MailKit.Security.AuthenticationException here
}


public class EmailMessage
{
    public string To { get; set; }
    public string From { get; set; }
    public string Subject { get; set; }
    public string MessageText { get; set; }

    public MimeMessage GetMessage()
    {
        var body = MessageText;
        var message = new MimeMessage();
        message.From.Add(new MailboxAddress("test", From));
        message.To.Add(new MailboxAddress("test", To));
        message.Subject = Subject;
        message.Body = new TextPart("plain") { Text = body };
        return message;
    }
}

应用程序密码

另一个选项是创建 apps passwords密码您之前使用的密码的位置。

using (var client = new SmtpClient())
    {
        client.Connect("smtp.gmail.com", 465, true);
        client.Authenticate("[email protected]", "appspassword");
        client.Send(message.GetMessage());
        client.Disconnect(true);
    }

smtp用户名的快速修复和密码不接受错误

Answer 2

看起来应用程序密码有效。您需要激活2个因子身份验证，然后Google为您提供16位数字密码。谢谢。