Our portal is open, which is not something we will change. But we still want to revoke access to one particular email that is being automatically added as a request participant. Instead of making automation rules that would update the ticket, we would like the user blocked from creating any tickets.
We have setup auto fwd from our support email to atlassian SD portal email, which creates tickets with the original sender, but it also takes the middleman (so to speak) as a request participant.
I see no option to really manage customers in portal. Nothing in admin, in project Customers tab it only lists "Resend Invite" and those have accepted have no actions available.