acceptance - the postal rule

what is the general rule for acceptance ?

if words aren't heard, what happens?
case?

how are instantaneous communications treated ?

when does communication take place according to the postal rule ?
case?

what is the criticism of this?

what did Bramwell LJ say about this?

what does Household Fire v Grant say about this rule ?

is there a way to avoid this rule?

case?

what about retraction of a postal acceptance?