Can you get a visa on arrival for Mozambique as an Australian citizen?
Citizens of all countries without a Mozambique embassy can obtain a visa on arrival if they have documentation to prove they are traveling for leisure purposes (return ticket, accommodation confirmation or invitation letter). This visa is valid for 30 days, and is extendable up to 60 days.
It seems that though Australia does have an embassy in Maputo, Mozambique does not have an embassy in Australia. This means you should be able to get a visa on arrival if your documentation is in order as per above.
But if I were you I would contact the relevant authorities in Mozambique by email to very this before going ahead too far with your planning. In fact, mts has found a source which claims that you might not get the visa on arrival despite the policy!