# 导包
　　首先我们需要导入 MailKit NuGet包，NuGet安装包命令在下方拓展介绍中。
# 引用命名空间
using MailKit.Net.Smtp;
using MimeKit;
# 邮件发送帮助类
 /// <summary>
 /// 发送邮件
 /// </summary>
 /// <param name="Name">发件人名字</param>
 /// <param name="receive">接收邮箱</param>
 /// <param name="sender">发送邮箱</param>
 /// <param name="password">邮箱密码</param>
 /// <param name="host">邮箱主机</param>
 /// <param name="port">邮箱端口</param>
 /// <param name="subject">邮件主题</param>
 /// <param name="body">邮件内容</param>
 /// <returns></returns>
 public async Task<bool> SendMailAsync(string Name, string receive, string sender, string password, string host, int port, string subject, string body)
 {
  try
  {
　　　　　　　　　 # MimeMessage代表一封电子邮件的对象
  var message = new MimeMessage();
　　　　　　　　　 # 添加发件人地址 Name 发件人名字 sender 发件人邮箱
  message.From.Add(new MailboxAddress(Name, sender));
　　　　　　　　　 # 添加收件人地址
  message.To.Add(new MailboxAddress("", receive));
　　　　　　　　　 # 设置邮件主题信息
  message.Subject = subject;
　　　　　　　　　 # 设置邮件内容
  var bodyBuilder = new BodyBuilder() { HtmlBody = body };
  message.Body = bodyBuilder.ToMessageBody();
  using (var client = new SmtpClient())
  {
   // For demo-purposes, accept all SSL certificates (in case the server supports STARTTLS)
   client.ServerCertificateValidationCallback = (s, c, h, e) => true;
   // Note: since we don't have an OAuth2 token, disable 
   // the XOAUTH2 authentication mechanism. 
   client.AuthenticationMechanisms.Remove("XOAUTH2");
   client.CheckCertificateRevocation = false;
   //client.SslProtocols = System.Security.Authentication.SslProtocols.Tls12;
   client.Connect(host, port, MailKit.Security.SecureSocketOptions.Auto);
   // Note: only needed if the SMTP server requires authentication
   client.Authenticate(sender, password);
   await client.SendAsync(message);
   client.Disconnect(true);
   return true;
  }
  }
  catch (Exception ex)
  {
  }
  return false;
 }