This is a script that was written by Fabio Olaechea and sent to me to be posted. It helps read the qmail logs a little easier from the command line. I translated it to English and lined up the formatting a little (probably got garbled in the email). Here's the output with no switches:
[root@mail ~]# ./qmlog usage: qmlog [option] service show current log of service 'service'
-l list backup logs of service
-s pattern show backup file of name starting with 'pattern' on service
-e regex show backup file that contain the string 'regex' on service
-t n show last n lines of selected file using tail
-p show with pause (using less)
--help this help
services: clamd imap4 imap4-ssl pop3 pop3-ssl send smtp spamd
Which will show you what it will do. I have not really tested the script, so you may want to view it before running it!
Here is the qmlog script 
Here it is in TEXT format 
Edit: works like a charm, invaluably helpful for the newly initiated. As an example, "#qmlog -p clamd" displays onscreen with human-readable time/date stamps the contents of /var/log/qmail/clamd with a pause...space bar/page-down to keep scrolling to EOF.