Abstract: Systems and techniques are provided for blockchain transactions where tokens of a first token type are transferred to a blockchain address of the second token type, the first token type being different than the second token type. In a specific implementation, a token exchange system receives blockchain blocks from one or more blockchain networks. The token exchange system identifies a wrong token type blockchain transaction in the blockchain blocks where the wrong token type blockchain transaction transfers tokens of the first token type to a blockchain address associated with the second token type. The token exchange system executes a fix token type blockchain transaction to correct the wrong token type blockchain transaction.

Abstract: Systems and techniques are provided for managing and categorizing unsolicited email from unknown senders using blockchain technology. In a specific implementation, an email authorization system authorizes email from advertisement campaigns to reach recipient email inboxes after the email is validated by executing blockchain transactions through the email authorization system. The blockchain transactions are recorded in a blockchain ledger in a blockchain network.

Abstract: Systems and techniques are provided for managing and categorizing unsolicited emails from unknown senders using blockchain technology. In a specific implementation, an email authorization system authorizes emails from genuine cold email senders to reach recipient email inboxes after the unknown senders validate the emails by executing blockchain transactions through the email authorization system. The email inboxes of the genuine cold email senders are monitored to detect responses to the sent emails. After a response is detected, a transaction using the first blockchain address is executed. The blockchain transactions are recorded in a blockchain ledger in a blockchain network.

Abstract: Systems and techniques are provided for managing and categorizing unsolicited emails from unknown senders using blockchain technology. In a specific implementation, an email authorization system authorizes emails from unknown senders to reach recipient email inboxes after the unknown senders validate the emails by executing blockchain transactions prompted by the email authorization system; else, the emails from unknown senders are not included in the recipient email inboxes. The blockchain transactions are recorded in a blockchain ledger in a blockchain network.