mongoose.connection.once('open', function() {
  User.find({}, function(err, users) {
    async.each(users, function(user, done) {
      console.log('in ' + user.email);
      async.waterfall([
        function(callback) {
          getInfos(user, callback);
        },
        function(infos, callback) {
          console.log('1 ' + user.email);
          User.update({ email: user.email }, {
            $set: {
              'infos.no1': infos.no1,
              'infos.no2': infos.no2
            }
          }, function(err) {
            console.log('2 ' + user.email);
            callback(null, 'updated');
          });
        }
      ], function(err, result) {
        done();
      });
    }, function(err, response) {
      console.log('DONE');
    });
  });
});

in user1@nope.com
in user2@nope.com
1 user1@nope.com
2 user1@nope.com
1 user2@nope.com
2 user2@nope.com
DONE

in user1@nope.com
1 user1@nope.com
2 user1@nope.com
in user2@nope.com
1 user2@nope.com
2 user2@nope.com
DONE