Get all results from an async function and add them to an array for a json response

Question

How can I get the mail_object.text results from simpleParser, and then add it to an array? This array is later returned in a json response.

https://nodemailer.com/extras/mailparser/#simpleparser

Here is my code:

app.get('/', (req, res) => {
//...query code

//parse
mail = [];
for (var i=0; i<result.length; i++) {
  simpleParser(result[i].mail.toString('utf8')).then(function(mail_object) 
  {
    console.log("Text body:", mail_object.text);
  }).catch(function(err) {
    console.log('An error occurred:', err.message);
  });

  mail.push({id: result[i].mail_id,
    body: //mail_object.text - add text body
  });
}

res.json(mail);
}