[FIX] mail: `Discuss` > `Send mail` sends a private message

For a message to be considered as a private message,
the message must have:
 - `no_auto_thread` set to `False`
   in other words, it must not be attached to a thread
 - no `model` or `res_id` must be set on the message
   meaning the message is not attached to a specific
   record thread.

See `_get_message_id` in `mail/models/mail_message.py`.

Before this revision, the mails sent from
`Discuss` > `Send mail` were not regarded
as private messages,
but as a kind of mass mailing messages,
with a `reply-to` wrongly set.
Any attempt to reply to these mails
failed with a delivery failure notification.

This was because the `message-id` of these messages
contained `reply-to`, and such message-ids are
treated as a special case in the messages routing
(basically, the match on the mail references is disabled
for these messages containing `reply-to` in
their message-id).

opw-669241

0 files changed, 0 insertions, 0 deletions