Add new reply_to_list option 'Reply-To: Poster, CC: list, Fr

[helly]

Add new reply_to_list option 'Reply-To: Poster, CC: list, From: list-bounces'.
This new option sets 'Reply-To:' field to the original Poster, the 'Cc:' filed
to the lest server and the 'From:' field to the list server with '-bounces'
suffix.

Rational:

Mail servers like Ford Motor Company block incoming addressed with internal
mail addresses in the 'From:' field as they identify this as a faked mail.
The solution is to use the Poster in the 'Reply-To:' field and the list server
in the 'Cc:' field. This way send reply and send reply to all still work.
However RFC [2]822 specify that a mail clients should not send a reply to
the from field for non explicit reply addresses like the 'Cc:' field. Thus
the 'From:' field cannot contain the list server address but will contain the
list server address with the bounces suffix.

The attached patch is against 2.1.9. The solution was also tested on 2.1.5
and 2.1.6 installations.

[helly (helly)]

The file mm-2.1.9.diff was added: Patch against 2.1.9