Every wallet gets a mailbox
Ethereum and Solana wallets become reachable handles, with Bitcoin-addressed mailbox support in progress.
wallet mailboxSMTP bridgeverified actions
Do you have a wallet? Then you have a mailbox.
Email can now reach wallets. Wallets can now email back.
Post3 turns every wallet address into a verifiable mailbox. Built for Ethereum and Solana, with Bitcoin-addressed mailbox support in progress. No token. No ads.
LIVE ROUTE PREVIEW
email world <-> Post3 <-> wallet
Normal email
Post3
Wallet mailbox
0xabc...@eth
7xKnQ...@sol
bc1p...@btc
Treasury notice
project verified + contract owner
Payment request
payout wallet matches signer
Email from legal@
DMARC passed + domain verified
What Post3 does
It makes wallets reachable without making everyone join another app.
Gmail and SMTP senders can email wallet addresses. A wallet owner can connect later and find messages waiting. When a project, payment request, or wallet action arrives, the message shows the proof it carries before the user trusts it.
What the inbox does
Six things every Post3 mailbox does.
A wallet mailbox should make origin, replies, actions, delivery, and integrations clear at a glance.
Normal email can reach it
Normal email senders can write to a wallet handle through the SMTP bridge before the wallet owner signs up.
Know if a message really came from the project
Every wallet signature, email authentication check, verified domain, project wallet, and contract ownership signal is shown in the message itself.
Wallets can email back
A wallet owner can reply with their wallet identity: a wallet-authenticated message, not just another email address.
Know what a payment request actually does before you sign.
Signed payment and action envelopes show signer, payee, network, asset, and risk before the wallet opens.
Ask someone to prove they control a wallet
A project can send a safe ownership-proof button. The recipient signs a purpose-bound message, and the partner gets a verified webhook result.
Choose how messages reach you
Users can choose in-app, email, webhook, immediate delivery, digest mode, quiet hours, mute windows, and history.
SMTP cold start
Messages can arrive before the wallet owner signs up.
This is the cold-start wedge: the address exists because the wallet exists. The owner connects later and the mailbox is already waiting.
A sender writes to a wallet-shaped email address from Gmail, Outlook, or any SMTP sender.
Post3 parses the chain namespace, validates the wallet handle, and stores the message for that wallet.
The wallet owner connects with a signature and can read, reply, forward, or route future messages.
SMTP bridge
sender writes
post3 routes
chain namespace + wallet handle resolved
wallet opens
messages are already waiting
Post3 Trust Panel
payment request proof
From
treasury.project.eth
Verified signer payout wallet
The signed payee wallet matches the wallet that authorized this action.
signature
SIWE verified
signer
0x9A3f...7B21
payee
0x9A3f...7B21
domain
DNS TXT passed
The wallet signed the message.
The payout wallet matches the signer.
The project identity checks passed.
Anti-phishing, not vibes
Stop guessing whether a message is real.
Post3 does not flatten everything into the same trust bucket. It shows the actual origin and the proof that came with the message.
wallet-authenticated wallet messages
DKIM, SPF, and DMARC
verified domains
verified project wallets
Safe owner checks
name-service records
contract ownership
sender reputation
Signed wallet actions
A payment request should not feel like a random DM.
Post3 can carry signed action envelopes inside a message, then ask the user to review exactly what the wallet will do before anything opens.
Payout verification shows whether the payee matches the signer or a verified project wallet.
EVM and Solana payment templates support native, ERC-20, and SPL assets.
Risk labels and action review keep the request readable before the wallet confirmation.
Action review
before wallet confirmation
payment request
25.00 USDC
network: eip155:8453
verified signer payout wallet
The signed payee wallet matches the wallet that authorized this action.
payment requestsopen linkssign messagestyped dataclaimsownership proofsgovernance votesdelegationSolana Actions
Wallet ownership proof
Onboarding a payout wallet should not require screenshots or blind trust.
Post3 ownership proof asks the recipient to sign a safe challenge that is bound to a wallet, domain, nonce, and request id. The result can be sent to a partner webhook and re-checked on the public proof page.
The signed message says it cannot authorize a transaction or move funds.
The proof verifies wallet control, not real-world identity.
Partners get a structured result they can store, audit, and verify again later.
Ownership proof
sign message > webhook
target wallet
0x742d...f44e on ethereum
challenge
domain + request id + nonce + expiry
result
verified signer + payload hash + proof url
This signature does not authorize a transaction or move funds. It only proves wallet ownership.
Delivery preferences
Email
forward to existing inbox
Webhook
signed events for systems
Digest
group quiet updates
History
diagnose and replay
Delivery controls
A mailbox is only useful if it reaches people where they already work.
Post3 supports in-app reading, external email notifications, webhooks, digests, quiet hours, mute windows, delivery history, and replay controls.
email
webhook
digest
quiet hours
mute
history
replay
For builders
Add Message, Pay, Vote, or Sign to any wallet address.
Explorers, wallets, marketplaces, DAO dashboards, and support tools can use deep links, widget snippets, APIs, and webhooks without building the messaging stack.
Contact wallet
Payment link
Action review
Wallet widget
Who is this for
The mailbox is for users. Teams get APIs, proof, and identity controls.
Start with the wallet mailbox, then send builders and projects to the pages made for them.
Wallet users
Open the live wallet inbox with email-origin messages, wallet-authenticated replies, and proof panels.
Wallet providers
Embed a verifiable inbox in your wallet. No token, no ads, no custody.
Developers
Use APIs, webhooks, deep links, widgets, recipient helpers, and message/action contracts.
Projects and DAOs
Prove domain, wallet, sender, Safe, name-service, and contract ownership before users trust a message.