Thanks for the suggestion Robert, but how do I find the time for which Postfix will not attempt a delivery after reaching the fail limit? Instead of outsourcing the task to script, and increasing a dependency, it would be better to keep it with Postfix itself, if possible.
If there aren't any options, I may have to go with the script. Then, I may need some more help... Thanks, DN Singh On Thu, Dec 1, 2011 at 1:29 PM, Robert Schetterer <rob...@schetterer.org>wrote: > 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 >
