On Wed, Oct 28, 2015 at 02:51:43PM -0400, Bill Cole wrote:
> From that point onward there are 5 distinct messages.
>
> If those are 5 different mailing lists, subscribers to multiple lists will
> receive multiple copies.
Not on properly configured systems. We're not talking about
subscribers who are on multiple lists. Rather each list received
5 copies. If some subscriber was on two lists, that subscriber
would have received 10 copies.
> This seems to me like it was entirely the work of the *sender* of that
> message. A single message was sent to 5 mailing list addresses and it got
> delivered to the subscribers of each of 5 mailing lists. This is a highly
> predictable (i.e.: perfectly normal) pattern of behavior by Mailman &
> Postfix.
No, cross-posting is perfectly fine and is not the sender's fault.
What's misconfigured is the interaction of the upstream multi-drop
mailbox and fetchmail.
> If you want the duplication to stop, get the sender to stop sending to
> multiple lists.
Please don't mislead the OP, he's got a difficult enough problem
to address.
--
Viktor.
