I'm a-guessin that the outer plate has a flap and the inner one don't. Put an outer in place of the inner. If you want to seal that sucker good, get a can of foam. Nobody will suspect a thing but the mail man will not be happy.

Or just take the inner plate off, put something flat behind it, put it back. Do foam.

Or call my Uncle Harry and he'll set you up with a nice new door. Full of foam.

Haha, well yes, part of this plan involves installing a mail box outside the door. When you say something flat, what are you thinking? Any idea when I can buy small flat metal plates online?

See below

Here is a link that might be useful: how to seal mail slot

Flat metal at the hardware store. Cut to size, drill a few holes, paint it, install. Or brass.

If you have a mail slot, you're probably in an older home. If not and your house is well insulated, I would leave it be because of the fresh air it lets in, even though it's cold outside. Now I want to sing, "Baby it's Cold Outside." lol

That's the best I can do on my first cup of coffee.

How are you going to get your mail if the mail slot is sealed off?

If you do want to do it, the easiest way is to just put some shrink wrap over it. Get some double-sided tape, make a square around the mail slot, attach some shrink wrap to the tape, then blow it with a hair dryer so it shrinks up nice and tight. Then just peel it off in the spring. If your door is painted, the tape could take some paint off with it when you take it off, so prepare for that.

we have one now, but have decided to put in a new door. you're right- they do let in more air than I expected... I thought there would be more of a weatherseal or something! if we wanted to keep our door, I would probably have looked into whether there is a more energy efficient mailslot to install...

Get a storm door.

Funny, my old mail slot had been covered up with brass plates. I thought you could buy the flat plates to cover it. I just installed a new mail slot and removed the mailbox. Love the mail slot. I bought a pouch to catch the mail so my dog doesn't eat it. Works great. I also have a storm door so that helps with insulation.

Here is a link that might be useful: Snail Sakk

Wow, thanks for all the feedback!

To answer one question, we are planning on getting a mailbox.

Interestingly, we already have a storm door, but we still get a lot of cold air. January and February, the cold air just pours in.

I tried asking about metal plates at Home Depot, but they were no help. I'll head over to the local hardware store -- maybe they will be more helpful.

The idea of a more energy-efficient mail slot is an interesting one -- I'll look into that.

It's a 1920 home with a beautiful wood door -- I'd hate to replace the door itself. Last winter, we folded up a hand towel and stuffed it in there. Worked great, looked silly.

Good to know spray foam is the way to go if we do seal it. I already have a can of Great Stuff too.

@sameboat Haha, love that story.

My husband cut a retangle from styrofoam or something similar to fit perfectly in the slot (we don't have an inside flap/plate, only the one on the outside). It worked wonderfully to block the incoming air.

Actually, I think it was some sort of foam insulation board, but it was several inches thick and filled the space in the door.

Actually, I think it was some sort of foam insulation board, but it was several inches thick and filled the space in the door.

@ sameboat...We had a similar story with a "killer mailbox"...suddenly it was dangerous and we had to adapt or change it. A union rep came to check out our modification...the neighbours all had rusty sharp ones, but that was okay. The letter carrier never returned, and the new ones asked why we had the "weird" set-up and asked us to remove it.

I have a mail slot but when I bought the house a few months ago and filed an address change I received a welcome from the carrier advising that postal regulations require a curbside mail box. I installed the box and now need to seal the door, preferably with a solid plate but don't seem to find any. Thoughts?

As it happens, I still haven't done anything about the mail slot. My plan -- if I ever get around to it -- is to measure the mail slot plates and replace them with solid plates of the same size that I'm hoping to order from onlinemetals.com. Before I seal off the slot, I'll fill it with insulation -- fiberglass, maybe? Ah, looking above, it seems people were suggesting spray foam.

fwiw, we didn't replace the door because of atypical measurements- more expensive than it was worth--- but i did replace with a mail slot that has 2 metal covers- one on the outside and one inside-- obviously not nearly as insulative as not having a slot in your door, but is better than having just the flap on just one side of the door as was here when we moved in!

Seems I often have bought something with some foam in the packing -- I'd cut a piece of that to fit inside for insulation (spray foam can't be controlled that well and is likely to require some messy clean up). you could either find or fashion a plate to cover the inside (another mail box slot from a salvage or resale shop, a door handle plate, a wood panel to coordinate with your door, etc.). You could secure the two together or use some silicone caulk to seal the flap shut in a way that could be removed if ever desired.

I had a mail slot in my door in Venice (CA), and the postman told me he would not deliver our mail until we put our names on the front door above the mail slot. So I had our names engraved on a brass plate (a friend who manufactures brass and bronze did this for me as a favor), and after I put it up, the postman delivered all kinds of random mail to us, regardless of the name on the address - plus mail that was for a different street with a similar name. It made me wonder where some of my mail may have been going. I also once caught him taking out a knife and slashing the Bird of Paradise plants along my sidewalk (He obviously did not like any leaves brushing against him), and so I reported this to his supervisor, who told me he would have a talk with him about this. After that, he stopped slashing my plants.

I never noticed any air or wind coming in the mail slot, but we did not get a lot of wind, and the house was a bit leaky anyway. Now I have a mailbox on the front porch beside the front door. I liked having the mail slot, but it would not go with the new front door that I have.

In the last 2yrs since I moved to the House I'm living in (1927 Cottage Bungalow) I've taken the wooden 15 panel door off 3 separate times,To attempt to stop the cold draft coming in the the mail slot in the door that is original to the House.Keep in mind,This door is not a style that a mail slot should be in,Or even look good in because whomever installed it,Just cut the hole & used a large sized mail slot,Which does not fit between the dividing rails & overlaps into the paneled areas.I've replaced it with 2 different types,Insulated the full view screen door with weatherstripping & a threshold in an effort to stop the air coming in,& even ripped pieces of wood the thickness of the door to basically install a rectangle to mount the mail slot flush with the panels,Yet nothing worked.Yesterday I ripped down a 6x6 (untreated) pine landscaping timer to the the proper thickness & then made it as wide & tall as the opening.My plan was to glue in the block of wood,Skim any areas with wood filler where the block of wood wasn't completely flush with the surrounding rectange "frame" blocking from the last attempt to seal out the air,Then cover the "patch" with a decorative polished nickel plate on either side but have the exterior side engraved with the word "Welcome".Your correct,I cannot find a retailer that sells them in a width that I needed ("4 x "12 to fit inside the "5 x "13.5 " patch) The only retailer I found was on Amazon but those backplates were no wider then "2.5.What I just ordered was a door push plate from Crystal Hardware,I ordered the "New York" in the polished Nickel finish because it looks better with My door,But I found styles I wasn't fond of on Signature Hardware's website also.These push plates are meant to go on the reverse of a swing door & is meant to be used opposite of a pull plate.Once I recieve it,I plan on taking it to My local mall that has a store called "things remembered" to pay that extra $ for engraving & fingers crossed,I'll NEVER have to take the door off it's hinges to mess with a repair ever again!! Yes they are charming & various people sell draft proof mail slots now,But they are ugly,purely utilitarian with zero form with all function.I bought a snail mail bag but it too was UGLY.Ebay sells a mail cage but it comes from the U.K....I rigged My own by purchasing a single metal file slot from Homegoods & cutting a rectangle hole,Then mounted it to the back of My door & the rear coverplate to the mail slot covered any raw edges.Worked perfectly to drop in after My mail carrier slid it through the slot.They also sell Baskets online made by Longaberger(?) Another option is to buy a mail slot with a shoot that has a locked "mail box" on the inside that has an angled shoot that slides the letters down to the box via gravity.Although mail slots will alway have a level of historic charm the way a milk door does,I'm a single Mom & it's not worth making My new furnace run non-stop due to the cross breeze of a draft between My front & back doors & costing Me a small fortune in heating bills.You could also look into buying a door insert that converts Your solid or paneled door to a french style glass door,And the inserts usually have argon gas/low E coatings to be energy efficant.That last option is for the readers who want to get a new door to do away with Their draft mail slot but have a bastard sized door.I hope one of these multiple suggestions helps solve Your problem.Trust Me,I understand Your frusteration of having the front door to Your Home become the bane of Your exsistance.It did it to Me,also...Until I finally had enough & glued in a wood patch.Gotta love Gorilla Glue & exterior wood filler!!!!! :) Problem solved :)

I used to live in Minnesota and when the winter comes the freezing air drafts are awful we used to put a cloth in the slot till my brother found a product online, it was really helpful, it did reduce the air drafts a lot and it also helps you catching your mail, it's really easy to install and it's really pretty, this is the website where you can take a look at it: snailsakk.com.

Cheers mate, i hope it heps you!

Don't you weatherproof draft

Just buy a draft dodger, weatherproof, mail slot

Thank you - I had not heard of the Draft Dodger Mail slot and why it never came up in my searches, I'll never know.

It's easier to use locking mailbox, for example, this one. I thougth that it's not popular at all nowadays

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