Martin Brennan 82cb67e67b
FIX: Canonical Message-ID was incorrect for some cases (#15701)
When creating a direct message to a group with group SMTP
set up, and adding another person to that message in the OP,
we send an email to the second person in the OP via the group_smtp
job. This in turn creates an IncomingEmail record to guard against
IMAP double sync.

The issue with this was that this IncomingEmail (which is essentialy
a placeholder/dummy one) was having its Message-ID used as the canonical
References Message-ID for subsequent emails sent out to user_private_message
recipients (such as members of the group), causing threading issues in
the mail client. The canonical <topic/ID@HOST> format should be used
instead for these cases.

This commit fixes the issue by only using the IncomingEmail for the
OP's Message-ID if the OP was created via our handle_mail email receiver
pipeline. It does not make sense to use it in other cases.
2022-02-03 10:36:32 +10:00
..