SMTP测试工具

SMTP服务器：smtp.exmail.qq.com
端口：465
安全：SSL
用户名：admin@company.com
密码：邮箱授权码
发送邮箱：admin@company.com
接收邮箱：test@xxx.com

【开始连接SMTP服务器 smtp.exmail.qq.com:465 SSL】
连接握手成功
账号验证通过
正在发送邮件至 test@xxx.com
邮件发送完成，无报错！

【连接失败】535 Authentication failed
账号或授权码不正确，请检查密码输入

// .NET Framework4.5 WebForm 一般处理程序 MailHandler.ashx
using System;
using System.Net;
using System.Net.Mail;
using System.Web;
using Newtonsoft.Json;

public class MailHandler : IHttpHandler
{
    public bool IsReusable => false;

    public void ProcessRequest(HttpContext context)
    {
        context.Response.ContentType = "application/json";
        var req = context.Request;
        string json = new System.IO.StreamReader(req.InputStream).ReadToEnd();
        var model = JsonConvert.DeserializeObject(json);
        string result = "";
        try
        {
            SmtpClient smtp = new SmtpClient(model.SmtpHost, int.Parse(model.SmtpPort));
            if(model.SecureType == "SSL")
                smtp.EnableSsl = true;
            smtp.Credentials = new NetworkCredential(model.User, model.Pwd);
            MailMessage mail = new MailMessage(model.SendMail, model.RecvMail);
            mail.Subject = "SMTP测试邮件";
            mail.Body = "这是SMTP工具测试发送的邮件";
            smtp.Send(mail);
            result = "【发送成功】邮件已投递至收件箱";
        }
        catch(Exception ex)
        {
            result = $"【发送失败】{ex.Message}";
        }
        context.Response.Write(JsonConvert.SerializeObject(new {Msg = result}));
    }
}

// 参数实体
public class SmtpModel
{
    public string SmtpHost { get; set; }
    public string SmtpPort { get; set; }
    public string SecureType { get; set; }
    public string User { get; set; }
    public string Pwd { get; set; }
    public string SendMail { get; set; }
    public string RecvMail { get; set; }
}