On Thu, 31 Mar 2011 14:53:11 -0400, Victor Duchovni <victor.ducho...@morganstanley.com> wrote: > Why would this be a response to "too many recipient commands", a > single message with many recipients is sent over a single connection, > unless you have set an ill-advised destination recipient limit.
All _recipient_limit parameters are all at their defaults. With the exception of things related to ciphers and TLS, we try hard to keep the default Postfix settings. > > /etc/postfix/main.cf > > slow_destination_concurrency_failed_cohort_limit = 3 # we give up > > after getting three 421 > > slow_destination_recipient_limit = 20 # keep it bellow 25 > > This increases the number of connections, which is unlikely what you > want, provided of course you have messages with a large recipient > count. It was not obvious to us. The idea was simply to put a limit on each burst of messages sent to the slow transport MTA's. These messages are related to a low traffic (2-3 messages a month), low volume (280 subscribers) mailing list, managed with mlmmj and using VERP tagging. We have exactly 142 subscribers from subdomains at .min-saude.pt. Hardly huge numbers. > > slow_destination_rate_delay = 1 # do not know if we really need this > This limits you to one connection at-a-time. The idea was to have a 1s delay between each message delivered. But, of course not knowing if this helped or not. > > /etc/postfix/master.cf > > slow unix - - - - - smtp > > -o syslog_name=postfix-slow > > -o smtp_connection_reuse_time_limit=30s Should we use only those 2 lines, or should we also add -o smtp_connection_cache_on_demand=no > > /etc/postfix/main.cf > > slow_initial_destination_concurrency = 2 > > slow_destination_concurrency_limit = 15 > > slow_destination_concurrency_failed_cohort_limit = 5 > > slow_destination_concurrency_positive_feedback = 1/5 > > slow_destination_concurrency_negative_feedback = 1/8 > > That depends on how determined the remote site is to damage the > SMTP eco-system by imposing counter-productive punitive mechanisms > on legitimate senders. Being it the health ministry bureaucracy, I am pretty sure that they have the time and resources to be creative at it. We know for sure that up until now they did not answer any emails regarding their strange mail server policies. > You can certainly try, and report your We will wait for your opinion on the above -o smtp_connection_cache... parameter, to try to those new settings. Thank you, M.
