I've experienced this, I thought it was due to the outlook update.
I've had a couple fiasco's where I didn't get any "your model failed to print" emails.
I added them to my safe senders list since but in previous years I didn't have this done at all.
I should have been more diligent in checking the order status through Shapeways website,
instead of crossing my fingers and hoping everything would just show up in time.
The other part that kept it silent was Shapeways now refunds entirely?
But they do it on the original transaction, or funds are held till order is complete?
I don't know exactly, but Paypal didn't notify of the refund either.