isoqlog是用来统计域里面的邮件的。通过查看qmail的log文件，来统计进出的邮件。
配置文件在/usr/local/etc下面，isoqlog.conf
#isoqlog Configuration file 

logtype     = "qmail-multilog"                          # log type qmai-multilog, qmail-syslog, sendmail, postfix
logstore    = "/var/log/qmail"                          #
domainsfile = "/usr/local/etc/isoqlog.domains"          #
outputdir   = "/www/isoqlog/log"                        # html output directory
htmldir     = "/usr/local/share/isoqlog/htmltemp"
langfile    = "/usr/local/share/isoqlog/lang/english"
hostname    = "xxx.com"

maxsender   = 100
maxreceiver = 100
maxtotal    = 100  

maxbyte     = 100