Consider this when you winterize your mailbox.
When the State, County and Town of Riga install any object, (mainly signs) in the Right-of-Way; they always use breakaway post systems. We would not do this unless forced to do so by the legal system. So when you are inspecting and repairing your mailbox system, do you really want to use any post that is any stronger than a 4×4?
Check with your insurance company, if they will cover any post stronger than a 4×4.
If your mailbox system is damaged during snow removal operations the Town Board has authorized a 4×4 post and the standard size metal mailbox as the only replacements, regardless of what you have installed.
The highway crew will repair any mailbox system they damaged to serviceable condition, not necessarily a new system.