Can templates be deleted so that nothing is sent out when the corresponding
action takes place.

For example, on one my lists, two or three messages go out whenever someone
subscribes, the standard welcome message, the $SIGNUP message, and the
"Output of your job" message, if it's an anonymous request. I'd like to
narrow this down to one or two messages. Can I delete the standard welcome
message? I saw a delete button at the bottom of the web interface for this
template but I wasn't sure of its purpose.

Thanks!