getMessageById() slows down - google-apps-script

Question

I am working on a script that works with e-mails and it needs to fetch the timestamp, sender, receiver and subject for an e-mail. The Google script project has several functions in separate script files so I won't be listing everything here, but essentially the main function performs a query and passes it on to a function that fetches data:
queriedMessages = Gmail.Users.Messages.list(authUsr.mail, {'q':query, 'pageToken':pageToken});
dataOutput_double(sSheet, queriedMessages.messages, queriedMessages.messages.length);
So this will send an object to the function dataOutput_double and the size of the array (if I try to get the size of the array inside the function that outputs data I get an error so that is why this is passed here). The function that outputs the data looks like this:
function dataOutput_double(sSheet, messageInfo, aLenght) {
var sheet = sSheet.getSheets()[0],
message,
dataArray = new Array(),
row = 2;
var i, dateCheck = new Date;
dateCheck.setDate(dateCheck.getDate()-1);
for (i=aLenght-1; i>=0; i--) {
message = GmailApp.getMessageById(messageInfo[i].id);
if (message.getDate().getDate() == dateCheck.getDate()) {
sheet.insertRowBefore(2);
sheet.getRange(row, 1).setValue(message.getDate());
sheet.getRange(row, 2).setValue(message.getFrom());
sheet.getRange(row, 3).setValue(message.getTo());
sheet.getRange(row, 4).setValue(message.getSubject());
}
}
return;
};
Some of this code will get removed as there are leftovers from other types of handling this.
The problem as I noticed is that some messages take a long time to get with the getMessageById() method (~ 4 seconds to be exact) and when the script is intended to work with ~1500 mails every day this makes it drag on for quite a while forcing google to stop the script as it takes too long.
Any ideas of how to go around this issue or is this just something that I have to live with?

Answer 1

Here is something I whipped up:
function processEmails() {
var ss = SpreadsheetApp.getActiveSpreadsheet().getActiveSheet();
var messages = Gmail.Users.Messages.list('me', {maxResults:200, q:"newer_than:1d AND label:INBOX NOT label:PROCESSED"}).messages,
headers,
headersFields = ["Date","From","To","Subject"],
outputValue=[],thisRowValue = [],
message
if(messages.length > 0){
for(var i in messages){
message = Gmail.Users.Messages.get('me', messages[i].id);
Gmail.Users.Messages.modify( {addLabelIds:["Label_4"]},'me',messages[i].id);
headers = message.payload.headers
for(var ii in headers){
if(headersFields.indexOf(headers[ii].name) != -1){
thisRowValue.push(headers[ii].value);
}
}
outputValue.push(thisRowValue)
thisRowValue = [];
}
var range = ss.getRange(ss.getLastRow()+1, ss.getLastColumn()+1, outputValue.length, outputValue[0].length);
range.setValues(outputValue);
}
}
NOTE: This is intended to run as a trigger. This will batch the trigger call in 200 messages. You will need to add the label PROCESSED to gmail. Also on the line:
Gmail.Users.Messages.modify( {addLabelIds:["Label_4"]},'me',messages[i].id);
it shows Label_4. In my gmail account "PROCESSED" is my 4th custom label.