Confirmation is used for two purposes in LISTSERV: security and
convenience. "Send= Open,Confirm" is a convenience rule: you just want to
make sure the address is valid. "Validate= All,Confirm" is a security
rule: you want to make sure forged commands are not executed. Security
rules always override convenience rules. Doing otherwise would mean
leaving some doors wide open while claiming that the list is secure. To
allow people to leave without confirmation, simply decrease the level of
security of the list.
Eric