var result = [];
    result.push({success : 1});
    for (var i = 0; i < rows.length; i++) {
    result.push({email : rows[i].email});
    };

[
  {
    "success": 1
  },
  {
    "email": "email1@email.com"
  },
  {
    "email": "email2@email.com"
  },
  {
    "email": "emailN@email.com"
  }
]

[
  {
    "success": 1
  },
  {
    "email": ["email1@email.com","email2@email.com","emailN@email.com"]
  }
]

var result = [];
var emails = [];

for (var i = 0; i < rows.length; i++) {
   emails.push(rows[i].email);
};

result.push({success : 1});
result.push({email: emails});

var jsonObject ;
jsonObject.success = 1;
var result = [];
for (var i = 0; i < rows.length; i++) {
result.push({email : rows[i].email});
};
jsonObject.email = result;

var result = [];
result.push({success : 1});
result.email = []
for (var i = 0; i < rows.length; i++) {
    result.email.push(rows[i].email);
};