Unsubscribe

Gmail and Yahoo require bulk senders to offer one-click unsubscribe, and other mailbox providers score mail better when it is there. Duta adds it for you.

Every message with a single recipient carries the List-Unsubscribe and List-Unsubscribe-Post headers (RFC 8058). Mail apps show them as an Unsubscribe button next to the sender’s name. You cannot set or remove these headers yourself.

When a recipient unsubscribes, Duta adds the address to your suppression list with the reason unsubscribe. Later sends to it answer suppressed, and the entry cannot be removed.

Messages to several recipients at once do not carry the headers, because one link cannot unsubscribe several people. Send transactional mail to one recipient per message where you can.