Ok Thanks. On Wed, Aug 31, 2016 at 3:32 PM, Wietse Venema <wie...@porcupine.org> wrote:
> Zalezny Niezalezny: > > Dear Colleagues, > > > > in our infrastructure we are using Postfix as a relay server which is > > responsible for transfering messages from our MS Exchange and Production > > systems. Our infrastructure include several Postfix relays: > > > > M$Exchange(lan) ---> Postfix1(middleware lan) ---> Postfix2(application > > lan) ---> Postfix3(web lan) ---> Internet > > > > I would like to ask You, what will happend if Postfix2 will be offline ? > > How Postfix1 will behave ? > > As required by SMTP mail standard, Postfix will retry the email up > to some time limit (with Postfix, maximal_queue_lifetime, default 7d). > > > M$ Exchange sending every minute ~10 000 E-mails. > > I recommend implementing Postfix2 etc. with multiple MTAs, perhaps > behind HaProxy load balancers. > > > *If outage will take longer, we need to store thousands of E-mails in the > > deffered queue, is there any limit for number of messages stored in the > > deffered queue ?* > > Your math is off. With 10000 messages per minute, that is over a > million email messages queued for every two hours of downtime. You > simply cannot afford days of downtime with such a volume. > > Wietse >
