CC Search Feature - populates unrelated users based on partial email match

When CC'ing an email in a ZD ticket that partially matches another email, it populates all partial matches as selections to CC. This seems unnecessary, as we are not searching, and rather pasting in an entire email. 

Ex: When pasting in "testuser1@gmail.com" to the CC field in a ZD ticket, the options of instead CC'ing "testuser123@yahoo.com" and "testuser1testing@hotmail.com" will also populate as options to CC on the ticket. 

Given that we're pasting in an exact email, populating completely unrelated user's seems like a privacy and security risk, given that they can mistakenly be selected to CC. Additionally, if the actual user (testuser1@gmail.com) doesn't have a user profile in ZenDesk yet, the other two, unrelated emails, will populate as selections ahead of the actual user we intend to CC.