Thanks for your response.
All mail has been forwarded but there's no sign of the book. I have seen this before where a 3rd party that is not USPS picks up an item and it disappears.
I used a Yahoo address for the order and found no emails from Telltale in the spam folder or anywhere else in the account. I do have a gmail address, but I did not use that for my Telltale order.
As it's "lost in the mail" I'm not sure what if any recourse I can take at this point.
Thanks again for the help and I'll search further for the emails from Telltale support.