On Fri, Aug 25, 2017 at 05:55:56PM +0300, Deniss wrote:
> Thanx, this looks useful
> Should config looks like following ?
>
> smtpfast unix - - n - - smtp
> -o default_destination_concurrency_limit = 20
No. Rather:
master.cf:
smtpfast unix - - n - - smtp
main.cf:
smtpfast_destination_concurrency_limit = 20
The destination concurrency limit is a qmgr(8) parameter, not a
delivery agent parameter.
> qmgr_message_active_limit = 200000
Yes, but ...
> relay_transport = smtp:backend
On MX gateway hosts that receive inbound mail, use "relay:..." not
"smtp:..." for your relay transport, and let outbound mail from
your system use "smtp". This reduces contention between inbound
and outbound traffic, in particular slow outbound mail will not
delay inbound mail.
> relay_domains = mydomain.com
> sender_dependent_relayhost_maps = inline:{prioritysender.com=smtpfast:backend
> }
No, because sender_dependent_relayhost_maps (unsurprisingly) only
changes the relayhost, not the transport. If your priority is by
origin, and not by destination, you may have to use three Postfix
instances, with low priority traffic shunted to the default slow
instance, and high priority traffic to the fast instance, with the
front end instance acting as a switch to separate the two flows.
Ultimately Postfix transport selection and concurrency limits are
(correctly) destination based, so to implement sender-dependent
behaviour you need to split the flow by sender, which can only be
done by handling off to another MTA (instance) with sender-dependent
relay settings.
You could use:
http://www.postfix.org/postconf.5.html#sender_dependent_default_transport_maps
but only when the destination domain is not a "relay" domain or
similar, that is, only if mail for the destination in questin just
goes whereever the MX records point with no transport overrides
beyond (sender_dependent_default_transport_maps) which selects a
sender dependent *default* transport.
--
Viktor.
