invite to a 3rd party

[Chav Paskov]

Trying to send invite to a 3rd party ( not user on system) . The recipient 
field on invitation form only allows to send invitation from the list of users 
on the system. Is there a config settings that
 i have to adjust in order to be able to send invite to any e-mail address?
Current build 3.2.1.
Regards
chav