This has been discussed at least a million time... A very long argument that leads to a rather simple situation. Either there is a GOOD REASON to add a "Sender:" field, or it doesn't really matter and both addresses do the same and go to the same person. If it doesn't really matter then it shouldn't really matter whether LISTSERV uses "Sender:" or "From:" to send its reply. If there was a GOOD REASON to add a "Sender:" field with a different address, then there is the same GOOD REASON for LISTSERV to use that field and not "From:", otherwise why insert it? The catch of course is that there is a third option: the case where a "Sender:" field was inserted that does not point to the same person, and where there isn't any good reason for inserting that field ("it looks cute", "I didn't read the RFCs carefully and I thought my gateway HAD to do it", etc). In that case the gateway should be changed. I really have a hard time understanding people who make their gateway put their (postmaster) address in the "Sender:" field, and then complain that they actually get mail as a result. As for "Reply-To:", LISTSERV does not use it to send command replies. This is a design decision, there are arguments for both cases. RFC822 does not mandate the use of the "Reply-To:" field, it is just a suggestion. Besides, there was no automated mail server when RFC822 was written. Eric