Issue Summary

User Search by user's email address on https://<site-name>.atlassian.net/wiki/users/userpicker.action doesn't return any result.

This page explains that we can search users by user's email.

Search for users by their user details eg: bob, Bob Smith, bob@example.com

Steps to Reproduce

1. Access a certain space permissions screen.
2. Edit permissions for Individual Users.
3. Click on the magnifier icon to explore the search of individual users.
4. Input a user's email address on the text box and click on the Search button

Expected Results

A user with the inputted email address is returned. Or be able to search for a user using a unique human readable string to identify users with the same name. 

Actual Results

No user is displayed.

Workaround

Search for users by user's Full name or Public name.