Unsubscription is automatic most of the time, but many things can cause
problems (mail addresses can change unbeknownst to the mailer (e.g. the
company's gateway is renamed). Also I suspect that majordomo was not
written to the same software standards as airplane control systems and it
doesn't always 'work'.
There is a human in the loop - Henry - who gets zillions of mail messages
every week due to this list (about 600 per weekend I think). Most of these
announce that someone has gone fishing or the company's server has gone
down. However Henry works through them and will take action on 'Please, I
can't unsubscribe'.
P.
Peter Murray-Rust, Director Virtual School of Molecular Sciences, domestic
net connection
VSMS http://www.nottingham.ac.uk/vsms, Virtual Hyperglossary
http://www.venus.co.uk/vhg