送受信のログをとる

root [100]# more extra.h
#ifndef EXTRA_H
#define EXTRA_H

#define QUEUE_EXTRA "Tlog\0"
#define QUEUE_EXTRALEN 5

#endif

として

root [100]# more /var/qmail/alias/.qmail-log
/var/log/usermail/usermail.log

root [100]# ls -al /var/log/usermail
drwxr-xr-x  2 alias  qmail      512  4 23 00:00 .
drwxr-xr-x  8 root   wheel     2048  4 23 03:06 ..
-rw-r--r--  1 alias  qmail        0  4 23 00:00 usermail.log