unique email address in customer registration
 

I have tried to register a new customer by using a duplicate email address already in the database and it gives me the error messages:

INVALID SQL: 1062 : Duplicate entry 'bhuang@worldlifegroup.com' for key 1
SQL QUERY FAILURE: insert into xcart_maillist (email, since_date) values ('bhuang@worldlifegroup.com','1060666299')

How can I reject the new registration with the duplicate email address in the database and ask them to use a unique email address?

Thanks in advance!

This has been mentioned a few times and is currently in the bug list to get fixed in future versions

Can you tell me if this has been implemented in at least Xcart 3.5.3?