Stephen, fascinating to know the (epic) background to Guss v Magistrates' Court. (That case is aired in summary hearings fairly regularly.)

I wonder if s 8 of the Electronic Transactions (Victoria) Act 2000 (http://tinyurl.com/md3hs7 ) might apply in cases like the one you mention? It would require consent — which presumably would require the client's agreement as part of the retainer — but might then satisfy the requirement for postal service.