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
