>But setting my ACK option doesn't work for a peer list wuch as this, This is caused by the UIUCVMD server beeing at 1.4c level. It works for 1.5 and better. W.r.t. the X-something idea, it is already used by LISTSERV: internally it passes options to a peer list via a 'X-LSVOPTS' tag. > The mail ACK >options is better for most users because they a) can set their own >default and b) have a documented way to change it. They can also with LISTSERV (and it *is* documented -- in the LISTSERV memos). I don't think that using the Acknowledge-To tag would be a good idea, because this changes the semantics for the tag (i.e., it is not clear what Ack-To means when mailing to a distribution list: acks from the server you mailed to, from all peer servers, from all servers used ›if never mail is hanldled via DISTRIBUTE!, or from all recipients ›aaughhhh :-) !). I tend to believe that those tags were not designed to interface with mechanisms such as list servers, but only for personal correspondence -- person to person. Jose M. Blasco P.S. I agree with you, it's a pain having to rely on the owners to change your options. Perhaps the checking for Validate=All could be bypassed in the case of options changing -- I cannot see any security problem here, probably an informative note sent to the owners would be sufficient.