Wietse Venema:
mailinglist: wietse, test, root
owner-mailinglist: root
test: test, t...@example.com
First, mail to 'mailinglist' is forwarded as a new message without
any mailbox or off-site delivery:
Jul 21 09:52:05 wzv postfix/pickup[3011]: 1A543A0033: uid=0 from=<root>
Jul 21 09:52:05 wzv postfix/cleanup[3023]: 1A543A0033:
message-id=<20160721135205.1a543a0...@wzv.example.com>
Jul 21 09:52:05 wzv postfix/qmgr[3012]: 1A543A0033:
from=<r...@wzv.example.com>, size=450, nrcpt=1 (queue active)
Jul 21 09:52:05 wzv postfix/cleanup[3023]: 1F2D4A0032:
message-id=<20160721135205.1a543a0...@wzv.example.com>
Jul 21 09:52:05 wzv postfix/local[3025]: 1A543A0033:
to=<mailingl...@wzv.example.com>, orig_to=<mailinglist>, relay=local,
delay=0.06, delays=0.04/0.01/0/0, dsn=2.0.0, status=sent (forwarded as
1F2D4A0032)
Jul 21 09:52:05 wzv postfix/qmgr[3012]: 1A543A0033: removed
As the next logfile record shows, the message has four recipients.
I captured the queue file, and found that the recipients are
r...@wzv.example.com, t...@wzv.example.com, wie...@wzv.example.com,
and the off-site address, t...@example.com
Jul 21 09:52:05 wzv postfix/qmgr[3012]: 1F2D4A0032:
from=<owner-mailingl...@wzv.example.com>, size=592, nrcpt=4 (queue active)
What happens next is that r...@wzv.example.com and wie...@wzv.example.com
get one message in their mailbox. The t...@wzv.example.com recipient
is alias-expanded, resulting in one email message in their mailbox,
and another off-site email for t...@example.com.
Without the 'owner-mailinglist' alias, all expansions would be done
in the same local(8) delivery request, which can de-duplicate aliases
so that everyone gets only one copy.
It's an old problem, and it is not likely to get fixed because
the fix would break at least one other thing.
Wietse
