I know with domestic express post they will refund the postage cost if it takes too long. It would be worth finding out from them if it's the same for international. Of course they will blame the US, but still worth grilling them about it and not taking no for an answer.

Have you signed up for My Post? I think the link is up the top of the AP home page. Might be worth it if you haven't. Every time you post something, you give them your My Post card to scan (which they scan after each parcel, so you have to give it to them with the first parcel) and you have full tracking via your computer or phone/device app. The app is still in its infancy so has its limitations, but for keeping an eye on tracking if need be, it's worth it. When they scan your card, it uploads that tracking number into the app. Occasionally one doesn't make it, so you can put it in manually.

If you log in to the My Post website you can set each transaction for notifications. That will send an email every time there is a tracking event. You even get one when it's due for delivery that day and again when it's delivered. There's a bit of a delay in notifications, but it's only like 10 or 15 minutes.

When you post, you can also give the PO the buyers email address, which they put into the system and then the buyer gets email notifications of each tracking event. I've only done that once, I wasn't sure if it was something buyers would want, or whether they may feel it's over the top.

The app will show you when the tracking numbers appear, then notify you when they're delivered. If you've ticked the notification box on the website, it will notifiy you of tracking events. You can set it so you don't get emails as well. I don't worry about the notifications, I'm just happy for it to tell me when they're delivered.

You can add a description of sorts to the tracking numbers, so I put the buyers name and ID and I've just started putting the ETA as well. That way I know who's parcel has been delivered and how close to the ETA it was (all have arrived before the first date). It saves having to go back and match up tracking numbers in eBay to the tracking numbers in the app. It's also easy to see at a glance if you have a buyer who says their item hasn't arrived yet. You can go straight to their tracking number.

It could be worth using it even if it's just for your international items.