Yes. If it were me, I'd send them quick polite and courteous message stating that as a conscientious seller, you like to keep an eye on outstanding packages in transit so that you are able to anticipate any issues that your valued customers might face. And as such you have noticed this parcel is being bounced between post offices (provide them the tracking number and link) and tell them not to worry, that if there are issues you'll get to the bottom of them. (As the sender, it has to be YOU who does it too. The receiver is pretty much powerless in circumstances like this.) You might also inquire that their address was correct and quote it back to them? It is a starting point if something is truly wrong.
I do same when this happens. I find that even when a buyer might be agitated that their item is not yet received, they are relieved to learn the seller will help them with whatever issues might arise. (I once had an order on the verge of being returned to me because the person's local small-town post-office kept telling them that they didn't have it. Tracking stated it had been there for more than 10 business days and the buyer had yet to receive their card saying it was available for pick-up. Then, when they went with a print-out of the tracking that stated it was waiting, they were refused. Twice. I had to call Canada Post. After that, the package was miraculously located in the back when my buyer went to get it. I still wonder what might have happened if I was not monitoring the situation. The item might have been sent back or 'set free to a new home' and my buyer would have been disappointed. It was a toy and Christmas was coming.)
Good luck as you carry forward.
