c#之无法发送电子邮件

string from = "myemail@gmail.com"; 
string to = "other.mail.123@gmail.com"; 
 
System.Net.Mail.MailMessage mail = new System.Net.Mail.MailMessage(); 
mail.To.Add(to); 
mail.From = new System.Net.Mail.MailAddress(from, "One Ghost", System.Text.Encoding.UTF8); 
mail.Subject = "This is a test mail"; 
mail.SubjectEncoding = System.Text.Encoding.UTF8; 
mail.Body = "This is Email Body Text"; 
mail.BodyEncoding = System.Text.Encoding.UTF8; 
mail.IsBodyHtml = true; 
mail.Priority = System.Net.Mail.MailPriority.High; 
System.Net.Mail.SmtpClient client = new System.Net.Mail.SmtpClient(); 
 
client.Credentials = new System.Net.NetworkCredential(from, "XXXXX"); 
client.Port = 587;  
client.Host = "smtp.gmail.com"; 
client.EnableSsl = true;  
try 
{ 
    client.Send(mail); 
} 
catch (Exception ex) 
{ 
    Exception ex2 = ex; 
    string errorMessage = string.Empty; 
 
    HttpContext.Current.Response.Write("errroorr " + ex.Message.ToString()); 
} 

它在 client.send() 方法中抛出异常。它说消息发送失败。可能是什么问题 内部异常是这个

内部异常显示 System.Net.WebException: Unable to connect to the remote server ---> System.Net.Sockets.SocketException: No connection could be because the target machine actively refused it 74.125.141.109: 587 在 System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot，SocketAddress 套接字地址)套接字和套接字、IPAddress 和地址、ConnectSocketState 状态、IAsyncResult asyncResult、Int32 超时、Exception 和异常)---内部异常堆栈跟踪结束---在 System.Net.ServicePoint.GetConnection(PooledStream PooledStream、对象所有者、 bool 异步、IPAddress 和地址, Socket& abortSocket, Socket& abortSocket6, Int32 timeout) 在 System.Net.PooledStream.Activate(Object owningObject, Boolean async, Int32 timeout, GeneralAsyncDelegate asyncCallback) 在 System.Net.PooledStream.Activate(Object owningObject, GeneralAsyncDelegate asyncCallback) 在 System.Net System.Net.Mail.SmtpConnection.GetConnection(字符串主机，Int32 端口)在 System.Net.Mail.SmtpTransport.GetConnection(字符串主机，Int32 端口)在系统.Net.Mail.SmtpClient.GetConnection() 在 System.Net.Mail.SmtpClient.Send(MailMessage 消息)

请您参考如下方法:

尝试添加这两个设置

client.DeliveryMethod = SmtpDeliveryMethod.Network; 
client.UseDefaultCredentials = false; 

还要检查您的服务器上是否有阻止发送电子邮件请求的防病毒软件