Your Child's
First Mailbox.
A childhood milestone
Already have a PO Box? Join MailDay →
The first time a kid turns their own key, opens their own little door, and pulls out a letter addressed to them — that's the kind of first you don't get many of. Here's how to give them one.
Their first mailbox. Just like Poppy's.
Bigger than it sounds
Poppy has a bright red mailbox at the end of her lane. It's always full. It belongs entirely to her. It's where every adventure starts and ends.
Your child can have exactly that. Their own key. Their own door. Their own address. Real things — not symbolic ones.
A first mailbox is a real address in the world.
Ownership
The key is theirs. The mailbox is theirs. The letters inside are theirs. Nothing to share.
The Real Magic
It looks like a small metal door. It's actually four big things.
What a first mailbox
gives a child.
Responsibility
They are the keeper of the key. They decide when to check the mail. They manage their own address. Real skills, disguised as fun.
Anticipation
Every mail day is an adventure. Is there something in the box today? Only one way to find out.
A Real Address in the World
Your child has their own address. A real one. That belongs to them. That's a bigger deal than it sounds.
The first trip to set up your child's mailbox should feel like the event it is. Four small things make it unforgettable.
The First Visit
Make it an event, not an errand
Build anticipation the night before
Tell them tomorrow they're going to see their very own mailbox for the first time. Let them fall asleep thinking about it.
Stand back when they open it
Let them put the key in, turn it, pull open the little door. Do not help unless they ask. That moment — the first time a child opens their very own mailbox — is one you will want your phone out for.
Let them carry the key
From the moment you leave the house the key is theirs to hold. They are the keeper of the mailbox. Do not carry it for them.
Make it a ritual
Every trip to check the mail should feel like a small adventure. After-school Fridays. Saturday mornings with a treat after. Whatever works — make it consistent enough that your child counts down to it.
The free 16-page guide
We wrote the whole playbook — from choosing a PO Box to the moment they turn the key. Get the printable guide free, straight to your inbox.
Everything You Need to Give Them Their First Mailbox.
Reserve It
Go to usps.com/poboxes to find and reserve a box online — or just walk into any post office and ask.
Two paths, both end with a key in their hand
Setting Up a PO Box Takes About Ten Minutes
1
What You'll Need
Two forms of ID (one photo), plus payment for the box. Prices vary a lot by location — from about $25 for three months to $100+ in bigger cities — so check yours at usps.com/poboxes. The smallest box is the cheapest and fits letters perfectly."
2
Which Size
Size 1 or 2 — the smallest, least expensive options. Your child's letters fit perfectly.
3
Give the Keys
You'll receive two keys. Give one to your child — tell them the one with the keychain is theirs.
4
Your child's MailDay address will be:
That's it. Your child now has their own address in the world.
USPS has 31,000+ locations across the US. In a rural area? A mailbox at a UPS Store works just as well.
[Child's first name]
PO Box [your box number]
[City, State, ZIP]
That's why we built Give a Key. At checkout, members can chip in to the MailDay Mailbox Fund with one click. Those contributions pool together and cover the PO Box for a kid who'd otherwise go without — a first mailbox, a first key, a first address of their own
Every kid should get to open their own mailbox. Cost shouldn't be what decides it.
Give a Key
Add $10 to the Mailbox Fund
Apply for a Sponsored Mailbox →
Applications reviewed within 48 hours. No income check, no judgment — just a mailbox for your kid.
Mailboxes sponsored
Children with their own address
States represented
A PO Box is safest — and most fun
A dedicated box means no home address is ever needed, and your child gets something entirely their own. Strongly recommended, never required.
Safety, plainly
MailDay is not an open platform. We review every match personally before either family is notified.
How We Keep Kids Safe
Addresses Stay Between Parents
When two kids match, we ask both parents to agree before anything is shared. Once you both say yes, we introduce you by private email and you exchange addresses directly — never publicly, never in a group. No address moves until both families have agreed.
The Rematch Guarantee
If a pen pal goes quiet, tell us — for any reason at all — and we find your child a new one. No questions, no charge, no long wait. Included with every membership.
Parents Supervise All Mail
We ask every family to read letters received and review letters sent before mailing. It's in our terms — and it's the single most effective safety measure there is.
Built around COPPA
All accounts are held by parents, never children. We never interact with kids directly or use their data for advertising. View or delete anytime.
Parents can request to view or delete their child's information at any time by emailing hello@joinmailday.com.
If something goes wrong
Email hello@joinmailday.com. We respond to safety concerns within 24 hours. Anyone who sends inappropriate content is removed immediately and permanently.
Dear Friend,
I have had my mailbox for as long as I can remember. It sits at the end of the lane outside my cottage — bright red, always full, always waiting.
There is something about having your own mailbox that feels different from sharing one. It says: this is mine. My letters come here. My friends write to me here. This is where my adventures begin.
I hope you love yours as much as I love mine.
Yours by post,
Poppy
P.S. The trick is to let them carry the key the whole way there. Trust me.
A few questions we get a lot
Anything else?
Does my child's pen pal need a PO Box too?
No. Their pen pal can use a home address or their own PO Box. Either works perfectly.
Do I have to get a PO Box?
Absolutely not. A PO Box is an option — not a requirement. Many MailDay families use their home address and have a wonderful experience. This is entirely your call.
What if there's no post office near me?
USPS has over 31,000 locations across the US. If you're in a truly rural area a UPS Store mailbox works just as well for receiving letters.
Can I use the PO Box for other mail too?
You can — but we'd suggest keeping it just for MailDay letters. Part of the point is that your child knows every piece of mail in that box is theirs.
How do I update my MailDay address after setting up a PO Box?
Email us at hello@joinmailday.com with your new address. We'll update your account and notify your pen pal's family within 48 hours.
What information does MailDay share about my family?
After a match, nothing is shared until both parents agree. Once you do, your child's first name and your mailing address go only to your pen pal's parents, by private email — never publicly, never in a group. Your family's full names are never published anywhere in MailDay.
What happens if I have a safety concern after joining?
Email hello@joinmailday.com immediately. We respond within 24 hours — usually much faster. Any safety concern is treated as the highest priority regardless of what it is.
The mailbox comes first. The pen pal comes next. Then the letters. Then the moment when your kid runs inside holding something addressed specifically to them — and you realize this was the right call.