Thanks for the quick reply. Your solution seems to be a very good one, but unfortunately that default_destination_rate_delay parameter is not available in the postfix version I'm running (2.3). I'm using the postfix implementation shipped with RHEL 5, which is not the most current one.
- Kenneth On Tue, Mar 22, 2011 at 10:32 AM, Reindl Harald <h.rei...@thelounge.net> wrote: > > Am 22.03.2011 09:05, schrieb Kenneth Holter: >> Hi all. >> >> I'm new to the list, and quite new to postfix. >> >> I'm running postfix 2.3 on one of my RHEL 5 servers, and have set up >> postfix to forward all emails to our Microsoft Exchange >> infrastructure. >> On the server running postfix, I have an applications that >> automatically generates emails. The issue I'm trying to solve is that >> at times, the application generates enormous amounts of emails, >> causing nearly a DoS attack on the Exchange servers. >> >> What I'd like to do is to have my postfix server rate limit the number >> of emails it's forwarding to the Exchange servers. For example, if I >> could get it to queue up emails, either on the inbound side or the >> outbound side, and forward them on a steady rate, that would be great. >> Note that all emails are generated locally on the server. >> >> Postfix seems to be a rather complex software, and I've not been able >> to identify which component I should be tuning to accomplish rate >> limiting. Any advice on this is greatly appreciated. > > we are using this setting to only send one message per destination and second > the problem is that "default_destination_rate_delay" only accepts whole > seconds as delay and it depends on the count of messages if you can > live with this, with < 10.000 mails per day 1 second delay for every > destination is ok > > initial_destination_concurrency = 5 > smtp_destination_concurrency_limit = 5 > default_destination_recipient_limit = 15 > default_destination_concurrency_limit = 5 > default_destination_concurrency_failed_cohort_limit = 5 > default_destination_rate_delay = 1 > transport_retry_time = 30 > > if there are too messages for wait a second maybe you > should set concurrency even lower and disable rate_delay > >
