The problem described in this KB article has been completely fixed since Plesk version 10.4.x.
After migrating/upgrading to Plesk 10 from versions <=9.x, mail users can see other mail users in their Plesk on the tabs Mail and Users. How to prevent this?
During migration/upgrade of Plesk to version 10, mail users are transferred to SMB users of the role Mail User with an assigned mail account of the same name. All SMB users belong to the same customer, the owner of the domain subscription.
According to their role, an SMB user may log in to the Plesk to see/edit preferences of all subscriptions that belong to the customer. By default, mail users may see the preferences of all other users on the tabs User and Mail.
The administrator of Plesk 10 may configure permissions of the role Mail User so that SMB users do not see other mail accounts in the Control Panel on the Mail page. To accomplish this, log in to Plesk as
admin user and open the Control Panel of the domain subscription Subscriptions > example.com subscription > Users > User Role > Mail User . In the permissions list, find
Create and manage mail accounts and select
With version 10.2 and higher versions, it is possible to hide the Users tab in the Control Panel for any role that does not have the Manage users and roles permission enabled. For that, add the option disable_readonly_users_list into the table
psa.misc of the Plesk database with the
# MYSQL_PWD=`cat /etc/psa/.psa.shadow` mysql -u admin psa
mysql> insert into misc values ('disable_readonly_users_list', 'true');
Query OK, 1 row affected (0.00 sec)