creating a orogram where the code have to check if the CIN has a @ in the text

im going to write a small program where the user types in a email adress and the code have to check if the email includes a @: ive just started programing and this is what ive come up with so far:

#include <iostream>
#include <string>
using namespace std;

int main() {
  cout << "Skriv in en Epostadress: \n";
  string adress;
  cin >> adress;
  if (adress == "@"){
    cout << "Giltig!";
  }
  else {
    cout << "Ogiltig!";
  }

  return 0;
}