Has anyone successfully set a Default-Topic for their List?



I can't figure out if I need to create a list of Topics and then decide
which Topic out of that List should be the default or whether the
default-topic is a completely different Topic from the list of all Topics. I
have tried setting the Default-Topic both ways but still when I sign up for
the list after setting this default-topic I am not able to send mail
successfully to that Topic. Will each subscriber show that they are
subscribed to that Topic in the Listserv Admin. Web interface or will I just
know it exists because I have set that option?



Any help is appreciated.



Thanks,

Laura