What problem would you foresee with declaring the location of the queue directory using a relative pathname? Suppose you used ./tmp (for tmp under the current directory)? What if you were root when you tried this or were not where you thought you were?
The 
LogLevel
 (
L
) option uses 
syslog
(3) to record messages. Read the online manual for 
syslog
(3) on your system, and determine where 
sendmail
 logging information is stored. Does the logging level that we specified (9) produce too much or too little information? Use 
tail -f
 to watch that information while at the same time sending mail with the 
client.cf
 file.
Why did we specify a 
To:
 header when sending mail, when the recipient was already listed in the command line? What happens when you omit the 
To:
 header and send mail using 
client.cf
?