Get message sender address from Gmail API

Question

Let me preface my question by saying that I am not a JS dev, or even a web dev, so bear with me! I'm trying to create a gs script that deletes messages that are older than n months that have a certain label and are from a given sender.

I think I have it down, but the Gmail API getFrom() method seems to return the sender's address in the format "First Last" <[email protected]> rather than just [email protected]. Currently I can work around this by the fact that I know this information, but is there a better way of doing this so that the code operates solely on the actual email address?

My current code:

function auto_delete_emails() {

  var label = GmailApp.getUserLabelByName("foo");
  var sender = "\"Foo Bar\" <[email protected]>";

  if (label != null) {
    var delayDays = 30
    var maxDate = new Date();

    maxDate.setDate(maxDate.getDate() - delayDays);

    var threads = label.getThreads();
    for (var i = 0; i < threads.length; i++) {
      var messages = GmailApp.getMessagesForThread(threads[i]);
      var from = messages[0].getFrom();
      if (from == sender) {
        if (threads[i].getLastMessageDate < maxDate) {
          threads[i].moveToTrash();
        }
      }
    }
  }
}

I have seen a question that used a regex to fix this, but I barely understand regex, never mind how to apply in this context or how the example worked (or didn't!).

Suggestions for other improvements on this code also welcome.

Regex is the only way brother! var from = messages[0].getFrom().replace(/^.+<([^>]+)>$/, "$1"); — iJay

Tholle Tholle · Accepted Answer · 2016-08-17T12:02:11

I think extracting the email address from the From-header is your safest bet. You can use e.g. this great RegEx:

function extractEmailAddress(header) {
  return header.match(/[^@<\s]+@[^@\s>]+/)[0];
}

function auto_delete_emails() {

  var label = GmailApp.getUserLabelByName("foo");
  var sender = extractEmailAddress("\"Foo Bar\" <[email protected]>");

  if (label != null) {
    var delayDays = 30;
    var maxDate = new Date();

    maxDate.setDate(maxDate.getDate() - delayDays);

    var threads = label.getThreads();
    for (var i = 0; i < threads.length; i++) {
      var messages = GmailApp.getMessagesForThread(threads[i]);
      var from = extractEmailAddress(messages[0].getFrom());
      if (from === sender) {
        if (threads[i].getLastMessageDate < maxDate) {
          threads[i].moveToTrash();
        }
      }
    }
  }
}

Get message sender address from Gmail API

1 Answers