Thanks Sam - all that is done.
The issue is that since MYOB changed how they were processing via Pay Super and using Superchoice, Australia Post SMSF Gateway Service has not been receiving any notices of the contributions paid. Prior to this change as advised by Steven_M in his post "Important – changes to the way super payments are processed" notices were being processed via AusPost as required. The funds still get into my SMSF bank account.
Australia Post can't help - they say the problem lies somewhere in the MYOB/Superchoice system.
I may have to submit this to the MYOB Support team.