Aggregate Gmail unreads by sender using Google Apps Script

aggregate-gmail-unreads.gs

/**
*** Aggregate Gmail Unreads
***
*** A Google Apps Script for counting and sorting through unread emails
*** Works for both Gmail and Google Apps aka GSuite aka Google for Work aka Google Workspace
*** ES5 syntax must be used for .gs files, do not use ES6 or higher notation
***
*** Usage: go to script.google.com, create a new project, save and run this script, authenticate, and wait (< 6 minutes)
***
**/


// Enum for selecting the criteria to use when organizing senders
var SortOption = {
  SENDER_NAME: 0,
  FULL_EMAIL: 1,
  DOMAIN: 2
};

// Optionally set the sort option here by replacing DOMAIN
var sortOption = SortOption.DOMAIN;

function countUnreadEmails() {
  var query = 'is:unread';
  var start = 0;
  var max = 200;
  var allUnreadThreads = [];
  
  while (true) {
    var threads = GmailApp.search(query, start, max);
    if (threads.length === 0) {
      break;
    }
    allUnreadThreads = allUnreadThreads.concat(threads);
    start += max;
  }

  // allUnreadThreads should contain all the unread threads, fetched in chunks of 200
  // this bypasses the usual limit from the GmailApp.search() method

  var sendersCount = {};
  var totalUnreads = 0;
  
  for (var i = 0; i < allUnreadThreads.length; i++) {
    var messages = allUnreadThreads[i].getMessages();
    for (var j = 0; j < messages.length; j++) {
      if (messages[j].isUnread()) {
        var from = messages[j].getFrom();
        var senderName = from.split("<")[0].trim();
        var senderEmail = from;
        var senderDomain = from.split("@")[1].split(">")[0];

        var senderKey;
        switch(sortOption) {
          case SortOption.SENDER_NAME:
            senderKey = senderName;
            break;
          case SortOption.FULL_EMAIL:
            senderKey = senderEmail;
            break;
          case SortOption.DOMAIN:
            senderKey = senderDomain;
            break;
        }

        if (!sendersCount[senderKey]) {
          sendersCount[senderKey] = 0;
        }
        sendersCount[senderKey]++;
        totalUnreads++;
      }
    }
  }

  var sortable = [];
  for (var sender in sendersCount) {
    sortable.push([sender, sendersCount[sender]]);
  }

  sortable.sort(function(a, b) {
    return b[1] - a[1];
  });

  Logger.log("Unread email count by sender:");
  for (var i = 0; i < sortable.length; i++) {
    Logger.log(sortable[i][0] + ": " + sortable[i][1]);
  }
  
  Logger.log("Total Unread Emails: " + totalUnreads);
}