Permanently delete gmail message after some days - google-apps-script

Question

I'm using this script for deleting old messages from gmail every X days.
It functions correctly, however messages are sent to trash.
I want to delete the messages permanently without sending them to trash.
Someone can modify this script?
// The name of the Gmail Label that is to be autopurged?
var GMAIL_LABEL = "mylabel";
// Purge messages automatically after how many days?
var PURGE_AFTER = "21";
function purgeGmail() {
var age = new Date();
age.setDate(age.getDate() - PURGE_AFTER);
var purge = Utilities.formatDate(age, Session.getTimeZone(), "yyyy-MM-dd");
var search = "label:" + GMAIL_LABEL + " before:" + purge;
// This will create a simple Gmail search
// query like label:Newsletters before:10/12/2012
try {
// We are processing 100 messages in a batch to prevent script errors.
// Else it may throw Exceed Maximum Execution Time exception in Apps Script
var threads = GmailApp.search(search, 0, 100);
// For large batches, create another time-based trigger that will
// activate the auto-purge process after 'n' minutes.
// if (threads.length == 100) {
// ScriptApp.newTrigger("purgeGmail")
// .timeBased()
// .at(new Date((new Date()).getTime() + 1000*60*10))
// .create();
// }
// An email thread may have multiple messages and the timestamp of
// individual messages can be different.
for (var i=0; i<threads.length; i++) {
var messages = GmailApp.getMessagesForThread(threads[i]);
for (var j=0; j<messages.length; j++) {
var email = messages[j];
if (email.getDate() < age) {
email.moveToTrash();
}
}
}
// If the script fails for some reason or catches an exception,
// it will simply defer auto-purge until the next day.
} catch (e) {}
}
thanks

Answer 1

It's pretty simple all you have to do is get all of your message id's in an array and then use the following two lines.
var request={"ids":messageIdArray};
Gmail.Users.Messages.batchDelete(request, "me");
You will have to enable the Advanced Gmail API
batchDelete
So if the rest of your code actually works then this should do it:
var GMAIL_LABEL = "mylabel";
var PURGE_AFTER = "21";
function purgeGmail() {
var age = new Date();
age.setDate(age.getDate() - PURGE_AFTER);
var purge = Utilities.formatDate(age, Session.getTimeZone(), "yyyy-MM-dd");
var search = "label:" + GMAIL_LABEL + " before:" + purge;
try {
var msgA=[];
for (var i=0; i<threads.length; i++) {
var messages = GmailApp.getMessagesForThread(threads[i]);
for (var j=0; j<messages.length; j++) {
var email = messages[j];
if (email.getDate() < age) {
msgA.push(email.getId());
}
}
}
} catch (e) {}
}