使用ASP.Net发送电子邮件，而不在代码中泄露密码

using System;
using System.Net;
using System.Net.Mail;
using System.Configuration;

public partial class EmailSender : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        // 从配置文件中读取用户名和密码
        string username = ConfigurationManager.AppSettings["EmailUsername"];
        string password = ConfigurationManager.AppSettings["EmailPassword"];

        // 创建凭据对象
        NetworkCredential credentials = new NetworkCredential(username, password);

        // 创建电子邮件消息
        MailMessage message = new MailMessage();
        message.From = new MailAddress("sender@example.com");
        message.To.Add(new MailAddress("recipient@example.com"));
        message.Subject = "Hello";
        message.Body = "This is a test email.";

        // 创建SMTP客户端并发送电子邮件
        SmtpClient client = new SmtpClient("smtp.example.com", 587);
        client.EnableSsl = true;
        client.Credentials = credentials;
        client.Send(message);
    }
}

<appSettings>
  <add key="EmailUsername" value="your_email_username" />
  <add key="EmailPassword" value="your_email_password" />
</appSettings>