Am 01.12.2011 08:35, schrieb DN Singh: > Hello Group, > > I am trying some extra configuration for postfix where it would mark > some destinations as undeliverable. I have found that there are some > destinations, start deferring the mails (may be greylisting) for a > particular period of time (times ranging from 1min to 4hrs), and after > the time window is over, they accept mails properly. So, I would like to > configure per-destination dead time limit, where Postfix would not > attempt any delivery at all to a destination for the mentioned time. > > I tried configuring backoff-time, but it only comes into picture after > first attempt, which will get deferred, during time the destination is > differing. Next, I found > "default_destination_concurrency_failed_cohort_limit", but I was unable > to find to time for which it will remain dead. I know this is transport > configurable, so I can configure different time limits for different > destinations. This is because, I do not want any delivery attempts > during the time when a destination is marked dead. > > Is this possible? If yes, then how? > > Thanks. > DN Singh
perhaps put some kind of scripted hold on them if they are always the same or use ideas from http://www.postfix.org/QSHAPE_README.html#backlog Postfix version 2.5 and later: In master.cf set up a dedicated clone of the "smtp" transport for the problem destination. In the example below we call it "slow". In main.cf configure a short delay between deliveries to the same destination. /etc/postfix/main.cf: transport_maps = hash:/etc/postfix/transport slow_destination_rate_delay = 1 slow_destination_concurrency_failed_cohort_limit = 100 /etc/postfix/transport: example.com slow: /etc/postfix/master.cf: # service type private unpriv chroot wakeup maxproc command slow unix - - n - - smtp See also the documentation for default_destination_rate_delay. This solution forces the Postfix smtp(8) client to wait for $slow_destination_rate_delay seconds between deliveries to the same destination. IMPORTANT!! The large slow_destination_concurrency_failed_cohort_limit value is needed. This prevents Postfix from deferring all mail for the same destination after only one connection or handshake error (the reason for this is that non-zero slow_destination_rate_delay forces a per-destination concurrency of 1). -- Best Regards MfG Robert Schetterer Germany/Munich/Bavaria
