Fail to send smtp mail poco c++ - c++

Question

I am new to c++ and tring to send a mail using gmail smtp. I have done this in python but I am unable to do it in c++. I think I need to add startTLS() but it seems to be not defined. Please help me, I have tried my best. Searched the internet also could not find any thing.
#include <cstdlib>
#include <iostream>
#include <Poco/Net/SMTPClientSession.h>
#include <Poco/Net/MailMessage.h>
#include <string>
using namespace Poco::Net;
using namespace std;
int main(int argc, char** argv)
{
std::string Username = "farhantestingsmtp#gmail.com";
std::string Password = "cpguxktxoyibiybd";
std::string Receiver = "jattfarhan10#gmail.com";
std::string Name = "Jatt Farhan";
std::string Subject = "Hello!";
std::string Content = "TEXT OF THE EMAIL";
try
{
MailMessage msg;
msg.addRecipient(MailRecipient(MailRecipient::PRIMARY_RECIPIENT, Receiver, Name));
msg.setSender(Username);
msg.setSubject(Subject);
msg.setContent(Content);
SMTPClientSession smtp("smtp.gmail.com", 487);
smtp.open();
cout << "Before Login";
smtp.login(SMTPClientSession::AUTH_LOGIN, Username, Password);
cout << "After Login";
smtp.sendMessage(msg);
smtp.close();
std::cerr << "Sent mail successfully!" << std::endl;
}
catch (std::exception& e)
{
std::cerr << "Failed to send mail: " << e.what() << std::endl;
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
I have added my mail username and password, as it for testing. Thanks in advance.
I tried to add startTLS and could not do it as The SecureSMTPClientSession was not defined in my VS environment. I also searched the internet, but could not fix it.