I am finally getting around to making a mailbox mod for my MES30. I have read countless threads talking about it being OK to use a galvanized steel mailbox as the temps won't get high enough (unless a flareup on the AMNPS tray) to fume out the zinc. The only adjustable elbows they had in 3" at the Lowes today appear to be 30 ga galvanized steel. Does the same thinking apply to using these as the mailbox as the heat in the smoke should be even less the farther from the MB it goes? Thanks!