C#邮箱身份验证

                //身份验证
                if (!sfrom.ToLower().Contains("hotmail") && !sfrom.ToLower().Contains("hexun"))
                {
                    client.Credentials = new NetworkCredential(sSMTPuser, sSMTPpass);
                }
                client.DeliveryMethod = SmtpDeliveryMethod.Network;
                if (sfrom.ToLower().Contains("gmail"))
                {
                    client.EnableSsl = true;
                    client.Port = 587;
                }
                if (sfrom.ToLower().Contains("hexun"))
                {
                    client.Credentials = new NetworkCredential(sSMTPuser, sSMTPpass);
                    // client.Credentials = new NetworkCredential(sfrom, sSMTPpass);
                }
                if (sfrom.ToLower().Contains("yahoo"))
                {
                    client.Port = 587;
                }
                if (sfrom.ToLower().Contains("hotmail"))
                {
                    client.EnableSsl = true;
                    client.Credentials = new NetworkCredential(sfrom, sSMTPpass);
                    client.Port = 25;
                }