Check the list header; I suspect you will find both an "Auto-Delete="
keyword statement with the "probe(x)" parameter, and a "Renewal=" keyword
statement. Active probing is enabled by the "Renewal=" statement; passive
probing is enabled by the "probe(x)" parameter on the "Auto-Delete="
keyword statment. They are not mutually exclusive, i.e., it is possible
to enable both active and passive probing on the same list. See section
4.9 of the LISTSERV List Owner's Manual for more information.

Reference: <http://www.lsoft.com/manuals/1.8d/owner/owner.html#4.9>

--
Paul Russell
Senior Systems Administrator
University of Notre Dame