In PLESK, 7.5.2 in Server-wide mail preferences we are UNABLE to check : ( ) Use of short (webmaster) and full (firstname.lastname@example.org) POP3/IMAP mail account names is allowed When we check this we have the error in PLESK: Unable to allow the use of short mail names for POP3/IMAP accounts. There are mail names matching the encrypted paswords i have lots of customers that are using short names to get POP3. Se erros in /var/log/messages: "Jul 1 17:46:17 lp2 authpsa: checkmailpasswd: FAILED: cleber - short names not allowed from @ [18.104.22.168]" This option was checked before. Suddenly it changed ALONE! How to solve this ?