Comment by layer8

4 months ago

Only the customer domain owners can fix the underlying issue, which is a missing SPF/DMARC configuration.

They could make the ticket IDs unpredictable so you can't subscribe yourself to any existing ticket by sending it an email

Zendesk could refuse to allow "ticket collaboration" if customers had a missing or insufficiently secure SPF/DMARC configuration, or at least make customers check a box that says "Tickets may leak their contents to anyone who can send emails".

That doesn't sound right. Aren't these @zendesk.com addresses?