big mail.err Logfile

[Janko1000]

Hi Guys,

my mail.err Logfile is full with Logout Messages. The Log grows per Day 500MB.
How can i change it?

- Debian 6
- Parallels Plesk Panel v. 11.0.9
- Postfix

Jun 24 03:35:44 phi74107 pop3d: 1372037744.277624 LOGOUT, user=goergens@xxx.de, ip=[::ffff:111.222.333.444], top=0, retr=0, time=0, rcvd=12, sent=39, maildir=/var/qmail/mailnames/xxx.de/goergens/Maildir
Jun 24 03:35:44 phi74107 pop3d: 1372037744.316193 LOGOUT, user=goergens@xxx.de, ip=[::ffff:111.222.333.444], top=0, retr=0, time=0, rcvd=12, sent=39, maildir=/var/qmail/mailnames/ixxx.de/goergens/Maildir
Jun 24 03:36:44 phi74107 pop3d: 1372037804.73849 LOGOUT, user=goergens@xxx.de, ip=[::ffff:111.222.333.444], top=0, retr=0, time=0, rcvd=12, sent=39, maildir=/var/qmail/mailnames/ixxx.de/goergens/Maildir
Jun 24 03:36:44 phi74107 pop3d: 1372037804.96854 LOGOUT, user=goergens@xxx.de, ip=[::ffff:111.222.333.444], top=0, retr=0, time=0, rcvd=12, sent=39, maildir=/var/qmail/mailnames/xxx.de/goergens/Maildir
Jun 24 03:37:44 phi74107 pop3d: 1372037864.387497 LOGOUT, user=goergens@xxx.de, ip=[::ffff:111.222.333.444], top=0, retr=0, time=0, rcvd=12, sent=39, maildir=/var/qmail/mailnames/xxx.de/goergens/Maildir
Jun 24 03:37:44 phi74107 pop3d: 1372037864.391000 LOGOUT, user=goergens@xxx.de, ip=[::ffff:111.222.333.444], top=0, retr=0, time=0, rcvd=12, sent=39, maildir=/var/qmail/mailnames/xxx.de/goergens/Maildir
Jun 24 03:38:04 phi74107 pop3d: 1372037884.363406 LOGOUT, user=verkauf@xxx.de, ip=[::ffff:111.222.333.444], top=0, retr=0, time=65, rcvd=12, sent=39, maildir=/var/qmail/mailnames/xxx.de/verkauf/Maildir
Jun 24 03:38:04 phi74107 pop3d: 1372037884.469014 LOGOUT, user=amazon@xxx.de, ip=[::ffff:111.222.333.444], top=0, retr=0, time=65, rcvd=12, sent=39, maildir=/var/qmail/mailnames/xxx.de/amazon/Maildir
Jun 24 03:38:04 phi74107 pop3d-ssl: 1372037884.517231 LOGOUT, user=info@xxx.de, ip=[::ffff:111.222.333.444], top=0, retr=0, time=65, rcvd=18, sent=93, maildir=/var/qmail/mailnames/xxx.de/info/Maildir