Google Apps Script for Advanced Gmail Filtering

TLDR - I just found and used Google Apps Script to write a really cool Gmail filter, that stars any thread (into a separate star-section) that is from someone that I've sent email to before. (i.e. senders I actually know)

Google Apps Script is an online typescript IDE that lets you script together apps at google.. It's kind of terribly clunky and buggy, but it also is pretty amazing that there is some Intellisense in a browser, and this thing is now seamlessly running in the cloud every 30 minutes.

Here are some instructions for setting up Google Apps Script. My filtering script is below..

Why did I do this?

I finally reached a threshold with all the non-spam notification mail cluttering up my inbox.

I already have multiple-inbox sections configured, with starred messages in a different section on top. I used to manually create filters to star messages, from my boss, or my wife.. but this doesn't really scale.

What I've always wanted was to automatically star threads from people in my contacts, or people I've sent email to before. However, gmail filters can't do this.

Enter Google Apps Script. It's a generalized cloud hosted Typescript programming environment, where you can bind together scripted actions on Google products. Some of it is a big laggy and clunky, a bit like dealing with the world's slowest compiler, and a debugger that is broken. However, now that the script is working, it's pretty neat that this is all magically hosted in the cloud and running every 30 minutes.

Here is my script:

function prioritizeInbox() {

    

  console.log("code start...");

  

  // var firstThread = GmailApp.getInboxThreads(0,1)[0];

  var firstThread = GmailApp.search("in:inbox and (label:starred)", 0, 1)[0];

  firstThread.markUnread();  

   

  // Wrap the entire function in a try / catch, in case there is an error, log it.

  try {

   

    // Get the most recent threads in your inbox

    var NUM_THREADS = 50;

    var threads = GmailApp.search("in:inbox and (!label:starred)", 0, NUM_THREADS);

    

    console.log("fetched threads ... " + threads.length);

    // For each thread

    for (var t=0; t<threads.length; t++) {

      var thread = threads[t];

      console.log({msg:"thread", n:t, thread:thread});

      

      // Get the sender of the thread

      var senders_map = {};

      var messages = thread.getMessages(); 

      for (var msg_n in messages) {          

        var msg = messages[msg_n];

        var msg_sender = extractEmail(msg.getFrom());

        senders_map[msg_sender] = 1;

      }

      

      var senders = Object.keys(senders_map);

      

      console.log("thread senders : " + senders);

      

      for (var n in senders) {

        var sender = senders[n];

        console.log("checking sender : " + sender);

        if (isImportantSender(sender)) {

          console.log("*****   Starring message from .. " + sender + "     ******");

          

          GmailApp.starMessage(messages[0]);       // star the first message in thread   

          break;

        }

      }       

      

    }

  } catch (e) {

    console.log("Error..." + e.toString());

  }

}

function isImportantSender(sender) {

      

  // check user email

  

  var user_email = Session.getActiveUser().getEmail();

  // console.log("checking user email ... " + user_email);

  if (sender == user_email) {

    return true;

  } 

  

  // check gmail aliases

  var aliases = GmailApp.getAliases();

  // console.log("aliases... " + aliases);

  for (var n in aliases) {

    // console.log("checking alias: " + aliases[n]);                     

    if (sender == aliases[n]) {

      return true;

    }          

  }

  

  if (false) {

    // check if I they are in my starred folder

    var search_spec = "label:starred from:" + sender;

    console.log("starred search_spec = " + search_spec);

    var starred_threads = GmailApp.search(search_spec,0,5);

    if (starred_threads.length > 4) {

      return true;

    } 

  }

    

  // check if i've sent them mail twice before

  var search_spec = "from:me to:" + sender;

  console.log("convo search_spec = " + search_spec);

  var chats_with_contact = GmailApp.search(search_spec,0,5);

  console.log("chats_with_contact .... " + chats_with_contact.length)

  if (chats_with_contact.length > 1) {

    return true;

  }   

  

  return false;

}

function extractEmail(addr) {    

  var regex  = new RegExp("^[^<> '\"]@[^<> \"']$");  

     

  if (regex.test(addr)) {

    return addr;

  }

    

  var regex2 = new RegExp("^.+<([^ ]+@.+)>$");

  if (regex2.test(addr)) {

    var match = regex2.exec(addr);

   

    return match[1];

  }

  

  return addr;

  

  

}