如何向所有邮件扩展发送邮件？

Question

我正在尝试向 textbox1.text 字段中输入的电子邮件地址发送电子邮件。我向 Hotmail 发送电子邮件没有任何问题，但在尝试向 Gmail 发送电子邮件时出现错误。我正在使用此代码发送电子邮件。

    string to = Textbox1.Text;
    string subject = "Mail subject";
    string body = "Hello";
    
    string fromAddress = "[email protected]";
    string password = "xyz";
    
    string smtpServer;
    int smtpPort;
    bool enableSSL;
    
    string domain = to.Substring(to.IndexOf("@") + 1);
    
    switch (domain.ToLower())
    {
        case "gmail.com":
            smtpServer = "smtp.gmail.com";
            smtpPort = 587;
            enableSSL = true;
            break;
        case "hotmail.com":
            smtpServer = "smtp.office365.com";
            smtpPort = 587;
            enableSSL = true;
            break;
        default:
            MessageBox.Show("The specified email provider is not supported.");
            return;
    }
    
    SmtpClient smtpClient = new SmtpClient(smtpServer);
    smtpClient.Port = smtpPort;
    smtpClient.Credentials = new NetworkCredential(fromAddress, password);
    smtpClient.EnableSsl = enableSSL;
    
    MailMessage mailMessage = new MailMessage(fromAddress, to, subject, body);
    smtpClient.Send(mailMessage);

下面的文本显示了我在尝试发送电子邮件时遇到的错误。

SMTP 服务器需要安全连接，或者客户端未经过身份验证。服务器响应是：5.7.0 需要身份验证。了解更多信息

Answer 1

像这样更改你的代码；

string to = Textbox1.Text;
string subject = "Mail subject";
string body = "Hello";

string fromAddress = "[email protected]";
string password = "xyz";

string smtpServer;
int smtpPort;
bool enableSSL;
smtpServer = "smtp.office365.com";
smtpPort = 587;
enableSSL = true;

SmtpClient smtpClient = new SmtpClient(smtpServer);
smtpClient.Port = smtpPort;
smtpClient.Credentials = new NetworkCredential(fromAddress, password);
smtpClient.EnableSsl = enableSSL;

MailMessage mailMessage = new MailMessage(fromAddress, to, subject, body);
smtpClient.Send(mailMessage);