1 + 2 +3 + 4 + 5 = 1,004 For the Mailman

This seems to be a game of being different although it's possible the odd mailbox is for a house a cross the street.  Maybe the master number for the 5 boxes is in the 1,000's and these just represent the unit numbers.  Anyway, the conformity and variety caught my attention.  Hope you have a happy weekend (and gets lots of friendly mail).  As you can probably tell in large, the 6th mailbox is 1004.