I copied that from a suggestion by "rony" on the forum (http://www.spampalforums.org/phpBB2/viewtopic.php?t=3912&start=0&postdays=0&postorder=asc&highlight=)
please make command-line:
spampal.exe - for start
spampal.exe /quit - for exit application
It's usefull for batch command file:
or more sophistical:
(if thebat.exe is closed, spampal.exe is exiting)
I personally still don't think that it makes a lot of sense to run SpamPal on demand, however, on very old/slow machines it might help to reduce the overall load and memory consumption.