# 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;
  }