Let's say you have a web application that your customers log in to with their e-mail address or username. Let's say, for example, this applications uses LDAP for authentication. How do you get your customers to have the same username/password for JSM as they do for your site? Ideally they should have the same credentials and when the password is change in your application then it's synced over to JSM.
From what I've read this isn't possible. I'm hoping I'm overlooking something.
I'll add that customers in this scenario are using e-mail that is not on the verified/authorized Jira domain. (Not my company's e-mail). I think this knocks Jira Access off the list.