我正在使用以下代码发送电子邮件。代码在我的本地机器上正常工作。但是在生产服务器上,我得到了错误消息

var fromAddress = new MailAddress("mymailid@gmail.com");
var fromPassword = "xxxxxx";
var toAddress = new MailAddress("yourmailid@yourdoamain.com");

string subject = "subject";
string body = "body";

System.Net.Mail.SmtpClient smtp = new System.Net.Mail.SmtpClient
{
    Host = "smtp.gmail.com",
    Port = 587,
    EnableSsl = true,
    DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network,
    UseDefaultCredentials = false,
    Credentials = new NetworkCredential(fromAddress.Address, fromPassword)       
};

using (var message = new MailMessage(fromAddress, toAddress)
{
    Subject = subject,
    Body = body
})

smtp.Send(message);

在我的Gmail A/c上,我从生产服务器运行代码后收到了以下电子邮件

Hi , Someone recently used your password to try to sign in to your Google Account mymailid@gmail.com. This person was using an application such as an email, client or mobile device. We prevented the sign-in attempt in case this was a hijacker trying to access your account. Please review the details of the sign-in attempt: Friday, 3 January 2014 13:56:08 o'clock UTC IP Address: xxx.xx.xx.xxx (abcd.net.) Location: Philadelphia PA, Philadelphia, PA, USA If you do not recognise this sign-in attempt, someone else might be trying to access your account. You should sign in to your account and reset your password immediately. Reset password If this was you and you are having trouble accessing your account, complete the troubleshooting steps listed at http://support.google.com/mail?p=client_login Yours sincerely, The Google Accounts team


当前回答

更新2022

更不安全的应用程序方法不再工作

您应该迁移到GMail SMTP API

仅使用gmail id和密码发送电子邮件不再有效。您必须从谷歌云控制台设置api并创建OAuth凭据。

链接到谷歌云控制台

连结至官方指南

链接到一个简单的指南

原来的答案

这是一个安全问题。Gmail默认情况下阻止自定义应用程序访问您的电子邮件帐户。您可以将其设置为接受应用程序的登录。

登录您的电子邮件后,点击这里

这将带您到下面的页面

其他回答

Tomasz Madeyski的评论解决了我的问题…他告诉存在一个错误的SetDefaultCredential,他说:

问题是在UseDefaultCredentials setter中有这样的代码:this.transport. credentials = value ?(ICredentialsByHost) CredentialCache。DefaultNetworkCredentials: (ICredentialsByHost) null;它覆盖由凭证设置器设置的凭证。对我来说,它看起来像SmtpClient的bug。”

如果你输入smtpClient。设置凭证后UseDefaultCredentials = false…这一行设置为空这些凭据…

我真的看过很多想法,唯一的解决方案是这种方式(适用于不同的电子邮件提供商):

            try
        {
            ViewProgressbar("Try to connect mail-server...", progressBar1.Value = 20);
            string host = dsProvider.Rows[y]["POP_hostOut"].ToString();
            int port = int.Parse(dsProvider.Rows[y]["POP_portOut"].ToString());  //587
            string[] email = von1.Split('@');
            string userName = (dsProvider.Rows[y]["login"].ToString() == "email[0]@email[1]")? email[0]+"@"+email[1] : email[0];
            string password = layer.getUserPassword(listSender.SelectedValue.ToString());
            SmtpClient client = new SmtpClient(host, port);
            client.DeliveryMethod = SmtpDeliveryMethod.Network;
            client.UseDefaultCredentials = false;
            //A idea from MSDN but it not works. You got "The server response was: 5.5.1 Authentication Required."
            //System.Net.NetworkCredential myCreds = new System.Net.NetworkCredential(userName, password, host);
            //System.Net.CredentialCache cache = new System.Net.CredentialCache();
            //cache.Add(host, port, "NTLM", myCreds);
            ///cache.GetCredential(host, port, "NTLM");   //NTLM
            client.Credentials = new System.Net.NetworkCredential(userName, password);
            client.Host = host;
            client.Port = port;
            client.EnableSsl = true;
            client.Send(message);
            ViewProgressbar();
        }
        catch (SmtpException ex)...

我在部署到Microsoft Azure的应用程序中遇到了同样的问题。

SmtpException: SMTP服务器需要安全连接,或者SMTP服务器需要安全连接 客户端未被验证。服务器的响应是:5.5.1 认证要求。

首先,我在以下页面上批准了所有未知设备(一些来自爱尔兰的ip地址)(以gmail用户登录): https://security.google.com/settings/u/1/security/secureaccount

我对客户端进行了如下设置:

var client = new SmtpClient("smtp.gmail.com");
client.Port = 587;
client.EnableSsl = true;
client.UseDefaultCredentials = false;
client.Credentials = new NetworkCredential("my_user_name@gmail.com", "my_password"); 

只有当我在smtp-client上设置了以下属性后,它才开始工作:

client.TargetName = "STARTTLS/smtp.gmail.com";

因此,正如其他人所说的那样,自5月30日起,谷歌不再支持使用第三方应用程序访问该帐户。

为了能够从我的代码访问帐户,我必须做的是首先启用两步验证。

一旦这样做,我创建了一个应用程序密码。

然后我将生成的密码替换为我用来访问我的帐户的密码。换句话说,你需要用这个新的应用程序密码删除gmail帐户密码(我们用来登录gmail的密码),功能就重新上线了!

我希望这能帮助到一些人:-)

我有一个以前工作的代码,现在抛出这个错误。密码没有问题。也不需要将消息转换为base64。事实证明,我需要做以下几点:

关闭双因素身份验证 将“允许不太安全的应用程序”设置为“开启” 从生产服务器登录到您的gmail帐户 也请到这里批准登录活动 在生产服务器上运行应用程序

工作代码

    public static void SendEmail(string emailTo, string subject, string body)
    {
        var client = new SmtpClient("smtp.gmail.com", 587)
        {
            Credentials = new NetworkCredential("youremail@gmail.com", "secretpassword"),
            EnableSsl = true
        };

        client.Send("youremail@gmail.com", emailTo, subject, body);
    }

关闭双重身份验证

将“允许不太安全的应用程序”设置为“开启”(同页,需要滚动到底部)