She said it is mandatory since January 2021. I remember to have sent a bunch of packets last year, but I don’t remember to having to use EZPost to do so.
I really don’t know the answer to your question but i’m guessing that might be the case.
The reason I say this is because most of my orders from Amazon of recent comes via EZPost. I guess EZPost is their logistics platform for processing in-bound and out-bound parcels.
I asked to Post to send to the Baltics, and they do not even send things there, but I sent tings from Estonia to Taiwan so its odd. Estonia Post I think is private, maybe like Germany’s (is it DHL?)