I'm able to create a dummy user with an already existing & registered email id. But could there be any issues do to this?
if you have Allow emails to be registered multiple times? setting turned OFF then I do not see any issues...
Where is the setting? Even if it is off will I not be able a user with existing id from Admin?
admin panel --> configuration --> settings --> User Registration and Profile Options
though it is turned OFF, admin can create a new user with existing (& registered) e-mail ID