Email accounts exist but not displayed

Hello, i have an issue with cpanel one of the domains have serveral email accounts ( 12 ) but now only one of them is visable from cpanel !!! althogh the email accounts are exists in this path /home/USERNAME/mail/DOMAIN i followed the instructions below but did not worked ! hoststud.com/resources/why-does-the-cpanel-not-show-existing-e-mail-account.376/