Some people's e-mail system do not REPLY from the same address at
which they first subscribed; sometimes they are part of a cluster
configuration and their clusters have different names.  Sometimes
e-mail is received by different hosts due to MX processing -- it
is not always clear what address will be constructed in the RFC
headers then.
 
Some lists have multiple subscribers from a FQDN, and some have
but a single (or they have different subscriber options that
effectively make them a "single" user).  This makes a difference
in how LISTSERV constructs list postings to those users and what
other host(s) get involved in the Distribute (backbone) act.
 
Until this person gets their config corrected, you may add a
second list subscription for them, yet set their distribution
option to NOMAIL.  That way, they'll be able to submit items from
several addresses YET receive distributions at only one.
 
Please remember that "e-mail is not symmetrical."
 
--  co-owner:   INFOSYS, TQM-L, CPARK-L, ERAPPA-L, JANITORS, LDBASE-L, et -L
URL:mailto:[log in to unmask] "Never confuse the messenger with the message"