Greetings, we're looking to adopt JSM as a ticket system for external clients, who don't necessary have an account (or have otherwise gone through the invitation process).
The issue we have is when you try to create a ticket for a new customer, who hasn't gone through the invitation process -- say someone who calls in and gives you their email address over the phone, and a ticket is made in the process.
I wasn't able to get JSM to accept an unknown email address as the reporter, however if the ticket comes in from an unknown email (via an email request) the reporter field is perfectly happy with said previously unknown address.