story node created and file is saved to server, but file not attached to node

Hi, I have setup a mailhandler mailbox and feed importer. I believe? I have enabled the correct permissions. I am able to import emails and save the files on the server over IMAP:
- the subject is mapped to the node Title
- the origbody is mapped to the node Body
- message_id is mapped to GUID which is set as the Unique target

In MailhandlerParser.inc, the attachments are add to the message here (line 55):
$message['attachments'][] = new FeedsEnclosure($file, $attachment->filemime);

Do I need to map the mimeparts or attachments to something? What target? I have tried Body, References and Threading.

Is Mailsave still required? It seems like it is not? I have tried with it enabled and without.

I am trying to go through the code (newish to Drupal and PHP), and I don't see any of the Mailhandler hooks getting called, i.e.

/**
* Implementation of hook_mailhandler
*/
function mimerouter_mailhandler($node, $result, $i, $header, $mailbox) {
dd('..... entering mimerouter_mailhandler');
... produces no log output

Any ideas or tips on debugging?

-Rob