How does the Jira Cloud Migration Assistant duplicate email check work?

Summary

This document outlines how the JCMA plugin evaluates user records to return results for the duplicate email check.

Solution

When JCMA completes the preflight checks for email duplicates, it loads the list of all users from all activeUser Directories in whatever order of user directories may be configured on the product. From here, it then runs a distinct on the list by username and checks against this list for duplicate email addresses to return the results. In other words, two identical users that may exist in separate directories with the same username and email will be treated as one record.

So as long as this is the case, in which both records share an email address and a username (even though they may exist in different directories), JCMA will not flag the user records as duplicates. If there is a situation whereby the usernames are different across the directories OR if the email addresses are duplicated but the usernames are unique, JCMA will flag these records as duplicate email addresses since it perceives a different username as a separate user record.