> RFC # 822 > 4.4.2. SENDER / RESENT-SENDER > 4.4.4. AUTOMATIC USE OF FROM / SENDER / REPLY-TO Here is the catchy part: > o The "Sender" field mailbox should be sent notices of > any problems in transport or delivery of the original > messages. If there is no "Sender" field, then the > "From" field mailbox should be used. What 822 does is in effect bundle two different roles together. Role 1 is the person (or process) that actually transmitted the message. Role 2 is the person (or process) that handles the notices of problems. I see that in some cases, these roles would need DIFFERENT mail addresses yet there is no way to specify two different addresses. One (but not the only) solution is a new header to account for the difference. It will require a CHANGE to RFC822, not just a registered extension. THAT is what makes this so hard, and that is why there will be a lot of resistance to it. That assumes that a REJECT-TO field or something like it be used. What if instead we want to have SENDER point to LISTSERV and use something like NEWSGROUPS? Again a potential problem exists because we cannot be sure that an uncivilized mailer will not send something that looks like a LISTSERV command to LISTSERV. Even RFC822 admits there are bad mailers. I think the SENDER field is essentially useless as it is (ambiguous).