QQ邮箱发送邮件请参考:
https://blog.csdn.net/wk201403010114/article/details/83543770
//新浪
MailMessage mail = new MailMessage();
//发送邮箱的地址
mail.From = new MailAddress("发送邮件的新浪邮箱账号");
//收件人邮箱地址 如需发送多个人添加多个Add即可
mail.To.Add(收件人的邮箱);
//标题
mail.Subject = "Title";
//正文
mail.Body = "尊敬的用户,您的登录密码是:\n" + pass+",请妥善保管!";
//添加一个本地附件 (这个我没用,可以研究一下)
//mail.Attachments.Add(new Attachment(UnityPath));
//所使用邮箱的SMTP服务器
SmtpClient smtpServer = new SmtpClient("smtp.sina.com");
//SMTP端口
smtpServer.Port = 587;//或者465
//账号密码 一般邮箱会提供一串字符来代替密码
smtpServer.Credentials = new System.Net.NetworkCredential("发送邮件的新浪邮箱账户", "新浪邮箱的登录密码") as ICredentialsByHost;
smtpServer.EnableSsl = true;
System.Net.ServicePointManager.ServerCertificateValidationCallback =
delegate (object s, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslPolicyErrors)
{ return true; };
smtpServer.Send(mail);