Don't forget to take some photo ID to the post office, or they won't accept your package. You also have to fill out a customs declaration, so no fibbing about the contents!
The postie will type your drivers licence number into the computer when you lodge the package and form, and check that your address matches that on the form and the return address on the package. No ID, no return address - no package sent for you!
I was hoping I could take the lazy way out and have the kids walk the packages down to the post office, but they won't accept anything unless the person lodging the package can show photo ID.