Handling of List-Unsubscribe callbacks on server
问题 When adding 'List-Unsubscribe' email headers, what kind of handling is required on the server-side for the callbacks? It's possible to add both a mailto-link and a web-link to the header, in PHPMailer it could look like this: $email->AddCustomHeader("List-Unsubscribe: <mailto:unsubscribe@example.com?subject=Unsubscribe>, <http://example.com/unsubscribe.php?unsubscribeid=$id>"); But does the mailto-address have to somehow automatically handle the unsubscription, or is it okay if the request