In addition to Nathan's cogent comments, consider a
user-initiated:
 
SET * NOMAIL
vs.
UNSUB *
 
Then the commands to "undo" the "unsubscribe"  or "nomail"
 
NOMAIL maintains other non-default subscriber options e.g.,
TOPICS, REPRO, DIGEST/INDEX.
 
"don't take away my SET * NOMAIL"
 
/Pete Weiss, Penn State