Comment 16 for bug 334064

"Reply-To munging does not benefit the user with a reasonable mailer. People want to munge Reply-To headers to make "reply back to the list" easy. But it already is easy. Reasonable mail programs have two separate "reply" commands: one that replies directly to the author of a message, and another that replies to the author plus all of the list recipients. Even the lowly Berkeley Mail command has had this for about a decade."

- This doesn't actually apply in most mailing lists. The normal mailing list behavior is NOT to include the author in the reply, since they'll already get a copy of it via the mailing list.

"If you use a reasonable mailer, Reply-To munging does not provide any new functionality. It, in fact, decreases functionality. Reply-To munging destroys the "reply-to-author" capability. Munging makes this command act effectively the same as the "reply-to-group" function. We haven't added anything new, we've only taken away. Reply-To munging is not merely benign, it is harmful. It renders a useful mail capability inoperative."

- Not really, you can always reply to the author. Sane mail clients make it easy to fill that address in, either from past history with completion, or by selecting who you want to reply to from a list.

"If the Reply-To is munged by the mailing list, the value provided by the original sender is lost. Reply-To munging can make it impossible to reach the sender of a message."

- No, if you're replying to a message on a mailing list, the author's email is there in the From: field. You can get it just fine.

In general, this "considered harmful" document misses the most common case: replying only to the mailing list. That is quite difficult to do without Reply-To.

The "Principle of Least Surprise" dictates that a reply to an ongoing thread should be attached to that thread. That the thread is a shared mailing-list makes no difference. Without reply-to, the default behavior is to take a message off-list, or CC everyone involved, causing many extra copies that most people seem to find annoying.

This happens regularly on the ayatanna list, where threads diverge for a large number of messages before anyone even realises they're not on the mailing list any more.

"Guess what feature more and more people are asking for? A third reply command -- one that ignores any existing Reply-To header!"
- That's fine. The default shouldn't be to reply "to the author" but "to the message". If you want to get away from that default, and relpy in private to the author, that's a very different and non-normal behavior than replying to a thread on a mailing list.

I'd suggest this get reopened.