I'm the brand new owner of an apartrment, without an awful amount of personal experience in dealing with strata or the owners corporation (have previously rented apartments and always went through the agent instead).
There are currently two things which I need sorted: missing letterbox key, and access to the switchboard room as required by the electricity provider I am signing up with.
From what I have read it seems the majority of boring day-to-day issues like these go to the strata manager to sort out +/- pass on to the owner's corp for bigger decisions - which got me wondering: when, if ever, would an apartment owner need to contact the owner's corp directly?
Get through your REA.
Ask your building manager.