Timbers suited to exterior use will depend largely on the degree of exposure.
Typically hardwoods such as Blackbutt, Spotted gum, Merbau and Jarrah tolerate high levels of exposure well. In instances where the entry door is protected Victorian ash (Tasmanian oak) and US oak are also suitable.
All timbers irrespective of the location or durability will need to be protected with a suitable exterior finish and regularly maintained for the best results.