Your Child's
First Mailbox.
A childhood milestone
The moment a kid opens their own mailbox for the first time is one you'll want your phone ready for.
Already have a PO Box? Join MailDay →
Poppy Post 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.
A PO Box at your local post office gives your child their very own dedicated mailbox — completely separate from the family mail, with their own key to check it. Their name on the box. Their letters inside. Their responsibility to manage.
Their first mailbox. Just like Poppy's.
Ownership
The key is theirs. The mailbox is theirs. The letters inside are theirs. This is not something they share — it belongs entirely to them.
A first mailbox is bigger than it sounds
Their own key. Their own door. Their own address in the world. Real things — not symbolic ones.
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 wrapped in a genuinely fun experience.
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 PO Box should feel like an event — not an errand.
How to make the first visit
feel like the event it is.
The first visit
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.
Online (easiest)
Go to usps.com/poboxes to find available boxes at your nearest post office and reserve one online. Complete the process in person when you pick up your keys.
Quick setup
Two paths. Both straightforward. Both end with a key in your child's hand.
Setting up a PO Box
takes about ten minutes.
1
In person
Walk into any post office and ask to set up a PO Box. The staff will show you what's available and get you set up on the spot.
2
What you'll need
Two forms of ID — one must be a photo ID. Payment — boxes start at approximately $10–20 every six months depending on size and location.
3
Which size to choose
Size 1 or Size 2. The smallest and least expensive options. Your child's letters will fit perfectly.
4
Your child's MailDay address will be:
You'll receive two keys. Give one to your child. Tell them the one with the keychain is theirs.
That's it. Your child now has their own address in the world.
USPS has over 31,000 locations across the US. If you're in a rural area — a mailbox at a UPS Store works just as well for receiving letters.
[Child's first name]
PO Box [your box number]
[City, State, ZIP]
That's why we built Give a Key — MailDay's mailbox sponsorship program. When members check out they can add a $10 Give a Key sponsorship with one click. That $10 goes directly into the MailDay Mailbox Fund and covers another family's setup cost — giving their child their first mailbox, their first key, and their first address in the world.
Not every family can afford a mailbox.
We think that should change.
Give a Key
Sponsor a Mailbox — $10 →
Apply for a Sponsored Mailbox →
Applications reviewed within 48 hours. No income verification. No judgment. Just a mailbox for your kid.
Mailboxes sponsored
Children with their own address
States represented
We Review Every Family
MailDay is not an open platform. Every family who joins completes our onboarding form before a single match is made. Our team reviews every application personally. Any application that raises a concern is declined and refunded immediately — no questions asked on our end.
We reserve the right to remove any member from MailDay at any time for any reason. We don't take that lightly. We use it when we need to.
Safety, plainly
Two paths. Both straightforward. Both end with a key in your child's hand.
Setting up a PO Box
takes about ten minutes.
Addresses Stay Between Parents
When two children are matched MailDay introduces their parents via private email. Addresses are exchanged directly between parents — never publicly, never in a group setting, never anywhere a stranger could see them.
Your child writes their pen pal's first name on the envelope. You address the outer envelope with the full mailing address. Your child's full name is never shared publicly anywhere in the MailDay system.
The PO Box: Safest and Most Fun
Most MailDay families give their child a dedicated PO Box for their letters. Not because we require it — because once they understand what it is they want it.
A PO Box means no family's home address is ever necessary. It also means your child has something that belongs entirely to them. Those two things are not in conflict.
A PO Box is strongly recommended. It is never required. Many families use their home address and have a wonderful experience. That is always your call.
Parents Supervise All Correspondence
MailDay matches kids. Parents manage the correspondence.
We ask every family to read letters their child receives before passing them along and to review letters their child writes before mailing. This is stated clearly in our terms of service — and it is the single most effective safety measure available.
If you ever receive a letter that concerns you contact us immediately at hello@joinmailday.com. Any member who sends inappropriate content is removed immediately and permanently. No exceptions.
We Are COPPA Compliant
MailDay is fully compliant with the Children's Online Privacy Protection Act. All accounts are held by parents or guardians — not children. We collect information about children from parents only. We never interact directly with children or collect information from them. We never use children's data for advertising purposes.
Parents can request to view or delete their child's information at any time by emailing hello@joinmailday.com.
The Rematch Guarantee
If your child's pen pal goes quiet for more than 6 weeks — for any reason — contact us and we will find them a new pen pal. No questions asked. No extra charge. No waiting.
Included in every MailDay membership automatically.
If something goes wrong.
We hope it never does. But if it does — we want you to know exactly what happens.
Email us at hello@joinmailday.com. We respond to all safety concerns within 24 hours — usually much faster. Any member found to have sent inappropriate content is removed immediately and permanently.
MailDay is a small team that genuinely cares about every family in this community. When something goes wrong we treat it that way.
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 magic is that your child knows every piece of mail in that box is theirs. Mixing in other mail dilutes that a little.
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?
Your child's first name and your mailing address are shared only with the parents of your child's pen pal — and only via private email. Nothing is shared publicly. Nothing is shared in group settings. Your family's full names are never published anywhere in the MailDay system.
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.