In Confluence, when two people have the same display name, the watcher or @mention dropdown displays something like:

• John Smith (123456)
• John Smith (cc765432)

In cases where the userid is an arbitrary value, it can be difficult for the user to select the correct John Smith. In Jira, the email address is included, which is more helpful to users:

• John Smith - jsmith@domain.com (123456)
• John Smith - josmith@domain.com (cc765432)

I would like to see Confluence display the email address for users in a mention or watcher dropdown list to aid in choosing the right user entry, as Jira does.