Steps to reproduce:
- Login with an Admin
- Create a new user and add a valid email address for him
- Make sure the SMTP server isn't configured
- Log off
- Go to http://localhost:8080/xwiki/bin/view/XWiki/ResetPassword
- Type in the name of the user from step 2
- Click "Reset Password"
You get an informative message saying an e-mail was sent, when you should be receiving an error with a stacktrace since the SMTP server isn't configured.