SmtpClient 发送邮件

static void Main(string[] args)
{
MailMessage msg = new MailMessage();
SmtpClient client = new SmtpClient();
client.Host = "smtp.163.com"; //代理服务器 主机
client.Credentials = new System.Net.NetworkCredential("mailname", "mailps");
client.Port = 25;//端口： 
Attachment at = new Attachment("");//附件
msg.From = new MailAddress("from");//发件箱
msg.To.Add(new MailAddress("4444@qq.com"));//收件箱
msg.Body = "你好！\r\n 这是关于数据处理的相关内容,请查收！\r\n 此致\r\n"; //内容
msg.Subject = "测试邮件";//主题
msg.Attachments.Add(at);//附件
// client.SendCompleted += client_SendCompleted;
client.Send(msg);
}