[Mailman-Developers] Advanced Reply-To-Munging

[Sven Anderson]

Hi all,

here's finally my next proposal for a less broken but yet very useful 
reply-to-munging:

- Motivation

Non-technical users (generally) love defaults. They don't wanna have to 
choose between three different kind of reply buttons. And no-way they want 
to change their MUA they just got painfully used to (or even their mail 
address, as most of them are using webmail providers), just because of a 
stupid mailing list. So there's a user base who are mostly using webmailers 
and Outlook, and who just want to press "Reply" as they usually do, no 
matter if there is even a "Reply-To-All" button right next to it.

Although this is a big pain for us geeks, I think a great software like 
Mailman should offer options (not default behavior) to serve such a user 
base. That's why I think, that Mailman should offer an option to set the 
default behavior of the standard reply button. The question what the default 
behavior of the reply button should be has to be discussed in each lists 
user base, Mailman should offer the choice. Many list admins are very 
thankful, if they don't have to educate their users.

- Proposed solution

There is no RFC-way to set the default address for replies. The Reply-To 
header _replaces_ the From address in replies, which is something else than 
setting a default. That's why setting the Reply-To completely hides the From 
address (regarding replies) and therefore abusing it as a default breaks the 
reply-to-all function for instance, as it doesn't include the From address 
neither (which is correct, as long as the Reply-To address is an 
_replacement_ for the From address). Since there is no other way but to 
abuse the Reply-To header to control the default reply behavior, 
reply-to-munging has to take care of the From address too.

There are four possible default reply targets that I consider as useful and 
should be offered at least as a list-wide option. (If individual mails are 
sent out, like with VERP, a per-user option is the best of course.)

1. Author
2. List
3. All recipients and author
4. Explicit address

And this is, what I propose that Mailman should do in these cases:

ad 1) Author is the "default default target" ;-). So no munging needed at 
all, no problems.

ad 2) If Reply-To is already set, it is removed. Reply-To is set to the 
lists address. The old Reply-To or - if not existing - the From address is 
checked if it is a list member. If not, it is added as a "fake Cc" to the Cc 
header, in order to make the reply-to-all function work.

ad 3) If Reply-To is already set, it is removed. Reply-To is set to:
  - the lists address,
  - all addresses in To/Cc headers, that are no list members, and
  - the old Reply-To or - if not existing - the From address, if not a list 
member

ad 4) If Reply-To is already set, it is removed. Reply-To is set to the 
explicit address. The old Reply-To or - if not existing - the From address 
is checked if it is a list member. If not, it is added as a "fake Cc" to the 
Cc header, in order to make the reply-to-all function work.

Of course, with option 2-4 you still lose the reply-to-author function, but 
at least for 2 and 4 in exchange for a new function, which a standard MUA 
with just a reply and reply-to-all button doesn't offer.

Example: Me and two colleagues are the management board of a local radio 
station. We use Mailman as a "Deluxe-Alias" for both communication among us 
and as Alias for people who want to contact us. So a lot of mails on this 
list come from non-members. In these cases I either want to answer only to 
the list (my colleagues) or to the author and the list, but _never_ to the 
author alone. So it's obvious that in this case we would like to have the 
reply button going to the list, and reply-to-all going to all (including the 
author, what at the moment doesn't work). We want the default going to the 
list, not only because of our MUAs (Thunderbird, Mutt, Webmailer) only Mutt 
supports reply-to-list, but also because we want the default reply to be the 
least dangerous, which in our case is the list. Funnily enough, the mutt 
user wants the most, that the normal reply is going to the list. ;-)

I hope I could make clear my ideas and point of view.


Cheers,

Sven