Issue Summary

This is reproducible on Data Center: (yes)

There is a dedicated user table for JSM/Portal-only Customer users in Cloud, which helps review just Customer users. However, the "last login" information on that Portal-only Customer user table appears to show only when the given user last logged directly into the Service Desk portal. There are customers who interact with their tickets exclusively via email (both for logging new tickets and commenting on their existing ones), and the "last login" timestamp doesn't update for those users at all, giving an inaccurate picture of their interaction with agents. 

Steps to Reproduce

1. Customers create tickets via email and also add comments, attachments, etc exclusively via email.
2. User Management -> Jira Service Management (Portal only customers)

Expected Results

"Last active" date should appear for customers who create tickets, comment or interact with Jira via mail.

Actual Results

Only customer who log into Jira/Portal will trigger the Last Active date. 

Workaround

Currently, there is no known workaround for this behavior. A workaround will be added here when available