letterbox insulation

An external flap will be a Rube Goldberg affair - not necessarily a bad thing if it works, but it would look like poop. How about a magnetic flap on the inside? That's assuming it's a steel slot. If not, maybe using some polyurethane or silicone caulk to make your own gasket and/or swapping out the spring (assuming that it's spring- loaded and not gravity) for a stronger one.

on 12/17/2007 1:01 PM neilsolent said the following:

Mount a 3 sided wooden box on the inside of the door covering the mail slot with a lift door on the top to get the mail out?

Good idea, and it would work well. However I am not very handy with stuff like that. Think this may be the only option.

Thanks for the ideas. It is a steel slot. Any kind of caulking or filling just stops the flap from returning - as it isn't spring loaded (it returns under gravity only).

If it really bothers you, remove it, mount an outside mail box and repair the door opening with decorative trim. I think you will find that a replacement weather proof door mounted box to be a very pricey situation by comparison. Good luck.

Joe