At 17:28 04/18/2000 Tuesday , Louise Lawrence wrote:
 >Tue, 18 Apr 2000 10:58:32
 >
 >You have been  removed from the SOC-PHOB list by  Maelstrom  Administrator
 >  <[log in to unmask]>
 >
 >Tue, 18 Apr 2000 11:00:13
 >
 >You  have been  added to  the  SOC-PHOB mailing list by Maelstrom Administrator
 > <[log in to unmask]>.

Each LISTSERV hosting site defines listserv-administrators aka listserv-postmasters.  Each "owns" all lists at that site though they do NOT receive list-specific bounces.  Sometimes those postmasters do receive unrecognizable list bounces and take appropriate action; or they receive email from subscribers requesting some list service, when the subscriber could not (figure out how to) get in touch with the list's owner(s).

Additionally, each subscriber site has implicit "generic" administrator addresses that can issue DELETE commands for their customers.  Often, an "OK" confirmation (three-way handshake) is required.

In the good ol' days of BitNet, each site registered in a centralized db called NODES (and then email distributed via LISTSERV to the worldwide list of LISTSERV machines) a list of explicit site administrators.

/Pete