Greg Sims: > We are seeing: "has exceeded the maximum number of connections" in our > logs for domains associated with outlook.com. We have a transport > named "outlook:" in transport.regexp as follows: ... > This transport is configured as follows in master.cf: > > outlook unix - - n - 6 smtp > -o syslog_name=outlook
Are you using this for all outlook email, or only for u...@outlook.com? Note: this is a trick question. > We would like to use Per-Destination Connection Caching to increase > our throughput for "outlook:". Our mail server does not specify > "relayhost =" in main.cf. Is it possible to associate per-destination > caching with the "outlook:" transport? If not, what is the best > alternative? Did you mean: master.cf: outlook unix - - n - 6 smtp -o syslog_name=outlook -o smtp_connection_cache_on_demand=yes -o smtp_tls_connection_reuse=yes It's easier to do the reuse configuration in main.cf. main.cf: smtp_connection_cache_on_demand=yes smtp_tls_connection_reuse=yes Note that Postfix has "smtp_connection_cache_on_demand = yes" by default, but for TLS you have to turn it on because that is still relatively new. Sofar there haven't been problems with reusong TLS encryted connections. > If the answer is something like the following in main.cf: > > smtp_connection_cache_destinations = hotmail.com, hotmail.es, > hotmail.co.uk, outlook.com, outlook.es, live.com, msn.com You don't want to do that unless you must exclude some destinations. > should we try to include All the domains associated with "outlook:" so > even small volume domains are not counted as connections by > outlook.com servers? If this is the case, should/can we point > "smtp_connection_cache_destinations =" to a regexp file? > > We are not seeing "conn_use=" in our logs. Is it true that Postfix > will not log "conn_use=" for current releases? We are running > postfix.x86_64 2:3.3.1-12.el8. See above. You need to turn on smtp_tls_connection_reuse. Wietse