A test program to send mail using Gmail works well on localhost:3000, but the same code doesn't work on meteor.com

"meteor deploy testcode" uses Mailgun. Instead, I want to use Gmail. A small test program like below works well on 'localhost:3000'. But it returns error on 'meteor.com':

Error invoking Method 'sendMail': Internal server error [500]

How to use Gmail properly?

(I set Gmail account permission lower, and test program on localhost can send a mail through Gmail).

// test.html  
<head>  
  <title>test</title>  
</head>  
  
<body>  
  {{> test}}  
</body>  
  
<template name="test">  
  <input type="button" value="send mail">  
</template>  
  
// test.js  
if (Meteor.isClient) {  
  Template.test.events({  
    'click [type="button"]':function(){  
      var dateTime = new Date();  
      console.log(dateTime);  
      Meteor.call('sendMail',dateTime);  
    }  
  });  
  
}  
  
if (Meteor.isServer) {  
  
  Meteor.startup(function () {  
    var gmailAccount = {'eml':'user@gmail.com','pwd':'************'};  
    var st = 'smtp://' + encodeURIComponent(gmailAccount.eml) + ':' + gmailAccount.pwd + '@smtp.gmail.com' + ':465/'; check(st,String);  
    process.env.MAIL_URL = st;  
  });  
  
  Meteor.methods({  
    'sendMail':function(dateTime){  
      var to = 'user@gmail.com'; check(to,String);  
      var from = 'user@gmail.com'; check(from,String);  
      var subject = 'test'; check(subject,String);  
      var text = 'Time:' + dateTime; check(text,String);  
      var sendObj = {'to':to, 'from':from, 'Reply-To':from, 'subject':subject, 'text':text};  
      Email.send(sendObj);  
    }  
  });  
  
}

Solution

Gmail security check causes the error.
"Google account help" suggest 3 points. I did all of them and my code works as I expected.

Thank you.