Script not forwarding email attachments properly

Question

I'm using the following script to check my Gmail inbox for emails I've labelled (manually or with rules) as a Purchase Invoice and auto-forward them to my accounting software.

However, .pdf attachments (the Invoice) aren't forwarding correctly: looking at the forwarded email, the attachment isn't a true .pdf file (see image below script) and my accounting software cannot access the .pdf.

Any guidance on what is going wrong?

function FwdInvoices() {
  var getLabel = GmailApp.getUserLabelByName('Purchase Invoice');
  var setLabel = GmailApp.getUserLabelByName('Purchase Invoice/Processed');
  var recipient = 'xxxxxxx@mail.autoentry.com';
  
  var userId = "me";
  var label = "Purchase Invoice/Processed";
  var labelId = Gmail.Users.Labels.list(userId).labels.filter(function(e){return e.name == label})[0].id;
  
  
  var threads = getLabel.getThreads();
  for (var i = 0; i < threads.length; i++) {
    
    var thread = threads[i];
    var message = thread.getMessages()[0];
    var messageId = message.getId()
    
    message.forward(recipient);

    thread.removeLabel(getLabel);
    //thread.addLabel(setLabel) - not using this - see below why
   
    //add label to message only (not thread - if label applied to whole thread the sent message will have label applied and show up in 'Processed' label view.
    Gmail.Users.Messages.modify({"addLabelIds": [labelId]}, userId, messageId)
    
    //thread.moveToArchive()    
         
  }
   
}

Here's how the attachement looks, almost as if it's a file linked via drive instead of the actual file. If I click on it, I get prompted to select a cloud .pdf viewer, rather than the usual immediate .pdf preview.

Answer 1

When forwarding attachments with the GmailApp, attachments don't get automatically included

However, you can easily include them manually with advanced options.

Sample:

    var message = thread.getMessages()[0];
    var messageId = message.getId();
    var attachments = message.getAttachments();
    message.forward(recipient, {attachments:attachments});