apt-get install isoqlog

edit /etc/isoqlog/isoqlog.conf ganti sbb :
logtype     = "postfix"                                 
logstore    = "/var/log/mail.log"                       
domainsfile = "/usr/local/etc/isoqlog.domains"          
outputdir   = "/var/www/isoqlog"
htmldir     = "/usr/share/isoqlog/htmltemp"
langfile    = "/usr/share/isoqlog/lang/english"
hostname    = "my.domain.ru"
maxsender   = 50
maxreceiver = 50
maxtotal    = 50
maxbyte     = 100

restart isoqlog

Supaya berjalan setiap saat masukkan ke crontab

edit /etc/crontab atau jalankan crontab -e
	* * * * * /usr/local/bin/isoqlog 1>/dev/null 2>/dev/nul