This screen allows you to join or leave the BLOCKCHAIN list. To confirm
your identity and prevent third parties from subscribing you to the list
against your will, an e-mail message with a confirmation code will be sent to
the address you specify in the form. Simply wait for this message
to arrive, then follow the instructions to confirm the operation.
Alternatively, you can
login with your LISTSERV password
(if you have one) and update your subscription interactively, without e-mail