On Tue, Mar 22, 2011 at 5:45 AM, Brian Evans - Postfix List <[email protected]> wrote: > On 3/22/2011 8:33 AM, Kenneth Holter wrote: >> 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. >> > > The most recent release of Postfix is 2.8.2. 2.3 is ancient and no > longer supported for updates. > > Redhat now has RHEL 6 which, I believe, uses Postfix 2.7. > > There are reliable (S)RPM packages available for RHEL 5 that will get > you to the parameters/functionality you need. > The most common is by Simon Mudd referenced on > http://www.postfix.org/packages.html at http://ftp.wl0.org/official/ > > Brian > >> - Kenneth >> >> On Tue, Mar 22, 2011 at 10:32 AM, Reindl Harald <[email protected]> >> 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 >>> >>> > >
I don't think Simon has updated his Postfix (S)RPMs since RHEL 4. :( Kenneth's best option may be to just compile 2.8 and upgrade: http://stevejenkins.com/blog/2011/01/building-postfix-2-8-on-rhel5-centos-5-from-source/ SteveJ
