I have come to realise from past experience in the month.
1. DHL couriers here aint very smart. Do not recognise a unit intercom buzzer is bad enough, what is worse? Because they couldnt get into the block, theyy didnt have sense to leave " Sorry we cannot get you" delivery note. It happened thrice for the same delivery parcel, despite leaving instructions with the hotline for them to press the buzzer.
2. Fedex couriers fared slightly better. Do not recognise a unit intercom buzzer either. However, they have enough sense to leave a delivery note with tracking bill number outside at the main entrance door on its first attempt. So that at least i could call back and arrange next delivery. Left instruction for them tobuzz the intercom next time.
3. TNT couriers. Smartest of the express delivery lot! Could actually know to locate the buzzer and got my delivery on its first attempt with absolute no instructions!
PS: Unlike asia, none of the couriers here carry a mobile. So they couldnt phone you. Man, i miss asia service!