Problem Description:
There is currently no way to see when a portal-only Customer account last logged in or performed any activity on the CSM support portal. Due to which there is no automated or rule-based mechanism to flag, deactivate, or remove customers who have been inactive for a defined period. This ability helps admins to identify and clean up inactive customer accounts.

Suggested Resolution:
Surface a "Last Active" date for Customer accounts — visible in the Customers UI (/jira/customer-service/customers) and returned via the CSM Customer API — reflecting the last time the customer logged into or interacted with the support portal.
Allow admins to configure an inactivity threshold (e.g., 12 months) after which customers are automatically flagged, notified, or removed.

Workaround (if any):
None currently available. Activity can only be approximated by checking the date of a customer's last submitted request via JQL (reporter = "<customer_email>" ORDER BY created DESC), which does not reflect portal logins or views.