Any experiencing SEing Australian companies?

Hey guys,

New here!

Was wondering if anyone had any experience SEing companies from Australia, or even divisions of International companies e.g. Amazon.com.au?

Sorry for the newbie question, but how does one get around registered mail, when Australia post can confirm that the package arrived? If you say DNA, then they can just say that the post service say that they delivered it, therefore the responsibility is on you to receive it properly.

Cheers!