> On Mar 22, 2017, at 3:27 PM, Zalezny Niezalezny
> <zalezny.niezale...@gmail.com> wrote:
>
> My Mailman server is connected to one of my mail gateways responsible for
> forwarding messages to the client from the internet. As I see in the logs
> Postfix from Mailman server sending each message with multiple recipients
> inside. Is this correct or I need to change here something?
The most efficient, and least disruptive to other non-list traffic, way
to deliver mail to large lists is to avoid forwarding to intermediate
gateways, and have the list server connected directly to the Internet,
sending email directly to the MX hosts of each recipient's domain.
The list manager should emit a single message addressed to all
the recipients, with VERP enabled to disambiguate bounces.
I don't know whether Mailman can do this or not.
The most natural way to create large mailings with Postfix is to
use the ":include:" feature of aliases(5) to expand the subscriber
list to the underlying recipient list, set an "owner-alias" to
direct all bounces to the bounce processing engine and enable VERP
(the "-XV" sendmail(1) option) when injecting the message so that
bounce processing sees the actual failed recipient.
When all the recipients are in a single message, Postfix will
schedule delivery of other messages interspersed with delivery
of recipients of the jumbo message, and thus not starve out
other messages that arrive after delivery of the jumbo message
begins.
If you're routinely sending sending mail to large subscriber
lists, a dedicated outbound MTA just for the list traffic
may be a good idea.
Of course you'll have deliverability issues to deal with at
all the major providers, be prepared to enroll in their
whitelist programs, and work with their support staff to
resolve issues.
--
Viktor.
