<p>I mean it ought not to even be _possible_ to assign someone a task in your organisational ticket tracker if they&#39;re not in your organisation. The ticketing system should _make_ it impossible, to prevent doing it by accident, and also this kind of (semi?)deliberate abuse.</p><p>Why is it even possible to assign me a ticket if I don&#39;t have an _account_ on your tracker? The idea that you can assign tickets to any old email address is just ridiculous.</p><p>Being able to have an arbitrary email address on the ticket&#39;s CC list makes sense, at least sometimes. Some ticket trackers are public-facing, for external people to make support requests. You need to be able to keep the external requester up to date on progress. Fair enough. But _assigning work_ to an external person is not the same thing!</p>