Change.org ответ адресата - каким образом понимают что это адресат - Проверка подлинности

Судя по всему, используется специальная ссылка. которая доступна только в письме, отправляемом адресату.

Вопрос:

Hi! I need to know /security/ details about way of checking the authenticity
of the sender (Decision Maker email). Does Change.org engine check *DKIM*
signature?
DKIM: en.wikipedia.org/wiki/DomainKeys_Identified_Mail

Ответ:

Thank you for your email. When you create a petition on Change.org, we ask you to designate your 'Decision Maker'. While typing in your Decision Maker, you may see their name listed in a drop down menu. This means we have their contact information on record. We automatically notify the Decision Makers when you start your campaign and send additional notifications as more people sign your petition. A decision maker can respond to the petition using the email being sent to them.

If your Decision Maker was not found in our list, and you have added their contact information, we cannot verify the authenticity of the response.

Feel free to contact us if you have questions about this information or need help with anything else.