1. PHPUnit testing Most of the changes have been covered by Unit test. vendor/bin/phpunit --filter= "test_email_greetings" 2. Manual testing Only user edit profile page that need to test manually. 2.1 Setup requirements Install an email catcher. Example: Mailpit ( https://github.com/axllent/mailpit) SMTP Outgoing mail configuration:   0.0.0.0:1025 to smtphosts setting in Site administration > Server > Email > Outgoing mail configuration. Still on that page, set No-reply address to noreply@example.com . Enabled the emailchangeconfirmation in the Site administration > General > Securitry > Site Security Settings. Create a new user with " First " as the first name and " Last " as the last name. 2.2 Testing request of email changes Login as a newly created user Navigate to the Edit profile page Change the email address Click the Update profile button Open new browser tab and access * http://0.0.0.0:8025* (The Mailpit web UI) VERIFY the new email has the greeting text "Hi First," Logout Login as admin Navigate to Site admin >> General >> Language >> Language customisation Choose English (en) in the dropdown. Click the Open language pack for editing button. Wait until the progress bar is completed and then click the continue button. In the Filter strings: Select core >> auth.php in the Show strings of these components selection box. Fill the string identifier input with: emailupdatemessage Click the Show strings button Fill in the local customisation textarea with the below: Hi {$a->lastname}, You have requested a change of your email address for your account on {$a->site}. # Click the Save changes to the language pack button. Logout Login as a newly created user Navigate to the Edit profile page Click the cancel email change link Change the email address again Open new browser tab and access * http://0.0.0.0:8025* (The Mailpit web UI) VERIFY the new email has the greeting text "Hi Last,"