using MailKit.Net.Smtp;using MailKit.Security;using MimeKit;using System.Threading.Tasks;namespace ConsoleApp1{ public class MailHelper {  public static void Send(string email, string subject, string message)  {   var emailMessage = new MimeMessage();   emailMessage.From.Add(new MailboxAddress("tianwei blogs", "[email protected]"));   emailMessage.To.Add(new MailboxAddress("mail", email));   emailMessage.Subject = subject;   emailMessage.Body = new TextPart("plain") { Text = message };   using (var client = new SmtpClient())   {    client.Connect("smtp.hantianwei.cn", 465, true);    client.Authenticate("[email protected]", "******");    client.Send(emailMessage);    client.Disconnect(true);   }  }  public static async Task SendEmailAsync(string email, string subject, string message)  {   var emailMessage = new MimeMessage();   emailMessage.From.Add(new MailboxAddress("tianwei blogs", "[email protected]"));   emailMessage.To.Add(new MailboxAddress("mail", email));   emailMessage.Subject = subject;   emailMessage.Body = new TextPart("plain") { Text = message };   using (var client = new SmtpClient())   {    await client.ConnectAsync("smtp.hantianwei.cn", 25, SecureSocketOptions.None).ConfigureAwait(false);    await client.AuthenticateAsync("[email protected]", "******");    await client.SendAsync(emailMessage).ConfigureAwait(false);    await client.DisconnectAsync(true).ConfigureAwait(false);       }  } }}