So, I just got word through my office. As of Oct. 1, USPS is officially suspending international mail acceptance to Australia, until further notice. This is due to "unavailable transportation."
Effects:
Airmail - effective 10/1
International Priority Airmail - effective 10/1
International Surface Air Lift - effective 10/1
Priority Mail International - suspended 9/17
First-Class Package International Service - suspended 9/3
Commercial ePacket - suspended 9/3
International Priority Airmail Packets - suspended 9/3
International Surface Airlift Packets - suspended 9/3
Customers are entitled to a full refund of their postage costs when service to the country of destination is suspended.
Detailed procedures for refund can be found at
https://postalpro.usps.com/international-refunds
The International Service Alerts page has the most up to date information:
https://about.usps.com/newsroom/service-alerts/international/?utm_source=residential&utm_medium=link&utm_campaign=res_to_intl
Thus ends this Public Service Announcement.
ETA - Packages that were submitted prior to the above dates will supposedly transport the packages to their destination, but delays are to be expected. Anything submitted after those dates, for the specific services, will be routed back to the sender. It then goes on to talk about getting refunds.