Spammers must pay you directly to get an email through.
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How it works
Sending an email requires a fee of at least 0.18 xUSD as collateral.
The email is sent only after the fee is paid.
The recipient can set their anti-spam fee to any price for incoming email. Setting a fee of 0 xUSD accepts all email including spam.
If the recipient believes the email was sent in good faith and was not spam the recipient refunds the fee.
If the recipient is an xusdx.com user the recipient earns 95% of the fee and xusdx.com earns 5%.
This is all done in the xusdx.com web-based email client.
Requiring a fee ensures each email you get is worth it.
Anti-spam protocol
Email clients must set the headers
X-Anti-Spam-Address: haven_wallet_address
X-Anti-Spam-Coin: xUSD
haven_wallet_address is a single-use Haven subaddress created with:
curl -X POST \
-H 'Content-Type: application/json' \
-d '{"email": "the_xusdx_username@xusdx.com"}' \
'https://xusdx.com/api/wallet_address_create'
The haven_wallet_address must have received the fee and at least 1 confirmation. A haven_wallet_address can be used only once per email.
Why
Email spam is a problem. An untried solution is to have fees. Spammers can't afford the fees to send thousands of emails. Fees work in Bitcoin.
To stop human-like bots the fee must be over 0.01 xUSD.
When a company sends you a marketing email this consumes your attention but you don't get paid for it. It's the advertising platform who gets paid. The money goes to the middleman to send you spam.
Want to get paid directly? And name your own price? And stop spam?
Companies spend $10.9 billion annually on email marketing. They make money showing ads that sell you stuff with 40x ROI. xusdx.com stops the spam and gets you paid for the ads. Your attention belongs to you.
With xUSD this is the first time email spam is stopped with untraceable stablecoin micropayments. It adds Proof-of-Work for the email sender like Hashcash and pays the recipient.
Pricing
To keep the service free we plan to cover costs from the fees. Else we might charge some small ~$1 xUSD monthly fee.
There's no storage limit.