Program.cs

using System;
using System.Net;
using System.Net.Mail;
using System.Text;
using System.Threading.Tasks;

namespace MailVerifySDK
{
    internal class Program
    {
        // 配置SMTP账号、发信人邮箱和授权码
        private static readonly string SmtpAccount = "your_smtp_account@qq.com"; // 替换为你的SMTP账号
        private static readonly string SmtpPassword = "your_smtp_password"; // 替换为你的SMTP授权码
        private static readonly string FromEmail = "your_email@qq.com"; // 替换为你的发信人邮箱

        static void Main(string[] args)
        {
            string toEmail;

            // 检查是否通过命令行参数传递了收件邮箱
            if (args.Length >= 2 && args[0] == "-receive")
            {
                toEmail = args[1];
                Console.WriteLine($"您通过命令行输入的收件邮箱地址为：{toEmail}");
            }
            else
            {
                // 如果没有传递命令行参数，则提示用户在控制台输入收件邮箱
                Console.WriteLine("请输入收件邮箱地址：");
                toEmail = Console.ReadLine();
            }

            // 生成4位随机验证码
            string verificationCode = GenerateVerificationCode();
            Console.WriteLine($"生成的验证码为：{verificationCode}（仅用于调试，实际使用时不应显示）");

            // 发送邮件
            SendVerificationEmail(toEmail, verificationCode);

            // 用户最多可以输入验证码5次
            const int maxAttempts = 5;
            int attempts = 0;

            while (attempts < maxAttempts)
            {
                Console.WriteLine("请输入您收到的验证码：");
                string userCode = Console.ReadLine();

                if (userCode == verificationCode)
                {
                    Console.WriteLine("验证码正确！");
                    break;
                }
                else
                {
                    attempts++;
                    Console.WriteLine($"验证码错误！您还有 {maxAttempts - attempts} 次机会。");
                }
            }

            if (attempts == maxAttempts)
            {
                Console.WriteLine("您已达到最大尝试次数，程序将退出。");
            }

            Console.WriteLine("按任意键退出...");
            Console.ReadKey();
        }

        // 生成4位随机数字验证码
        private static string GenerateVerificationCode()
        {
            Random random = new Random();
            int code = random.Next(1000, 10000); // 生成1000到9999之间的随机数
            return code.ToString();
        }

        // 发送验证邮件
        private static void SendVerificationEmail(string toEmail, string verificationCode)
        {
            try
            {
                MailMessage mail = new MailMessage();
                mail.From = new MailAddress(FromEmail);
                mail.To.Add(toEmail);
                mail.Subject = "验证码邮件";
                mail.Body = $"[MailVerifySDK]您的验证码是：{verificationCode}，请在5分钟内完成验证哦（。＾▽＾）";
                mail.IsBodyHtml = false;

                SmtpClient smtpClient = new SmtpClient("smtp.qq.com", 587); // QQ邮箱SMTP服务器
                smtpClient.EnableSsl = true;
                smtpClient.Credentials = new NetworkCredential(SmtpAccount, SmtpPassword);

                smtpClient.Send(mail);
                Console.WriteLine("验证码邮件已发送！");
            }
            catch (Exception ex)
            {
                Console.WriteLine($"发送邮件时发生错误：{ex.Message}");
            }
        }
    }
}