Re: [mlmmj] What do you do with Gmail accounts?

On Tue, Mar 05, 2024 at 11:35:33AM +0100, Christof Thalhofer wrote:
> Hello,
> 
> I migrated a couple of Mls from Mailman2 to Mlmmj (1.3).
> 
> With MM2 we did Reply-To-Munging (replaced the original Reply-To header with
> 'Reply-To: list@listserver'.
> 
> Mlmmj does not allow this. I can add 'Reply-To: address@list' but I cannot
> delete 'Reply-To: from@home' with delheaders because then Mlmmj also removes
> the 'From:' header ... why ???
> 
> So if I set 'Reply-To:  list@listserver' in customheaders there are often
> two 'Reply-To:' in the headers of an outgoing mail:
> 
> 'Reply-To: from@home' (set by the author of the mail)
> 'Reply-To:  list@listserver' (set by Mlmmj)
> 
> which causes Gmail to bounce that mail.
> 
> Now we have the problem with a mailinglist that Gmail does not have a
> 'reply-to-list'-button.
> 
> It has the options 'reply' and 'reply to all'.
> 
> 'reply' answers to the address in 'From:' and the mail doesn't go to the
> list.
> 
> 'reply to all' answers to the addresses in 'From:' and 'List-Post:' creating
> dupes at the person whose mail was answered.
> 
> Reply-To-munging seems to be the only way to give Gmail-users the
> possibility to answer direct to the list. But is is impossible to be done in
> Mlmmj.
> 
> What to do?

If you rewrite headers such as Reply-To, this will almost certainly invalidate
the DKIM signature of the original message if you also keep the original
"From:" header. If you want to modify any signed headers, you *must* rewrite
the From: address.

There are only two possible solutions when it comes to mailing lists these
days:

1. Don't touch any headers, only add List-* headers (e.g. List-ID)
2. If you do change any headers, you *must* also rewrite the original From:
   header (e.g. by moving it to X-Original-From:), because otherwise you will
   violate DKIM/DMARC policies of the sender's domain

-K