Hi,
Thanks for the swift reply.
The SME server has been working fine for many months, I have the internal delegate mail servers IP address set. SME server is successfully delivering mail to it.
I just can't see any evidence that qpsmtpd is doing the check_smtp_forward test.
And this is allowing many emails to arrive at the exchange server for non-existent users, which are then bouncing. I could set exchange to drop them but I would prefer to not waste the bandwidth receiving them in the first place.
I expected that check_smtp_forward would reject the emails due the recipients address before the SME server had actually received it, and it was only today when I had a dig in the qpsmtpd logs that I could not find evidence to show it doing this.
Oddly I know my old 7.6 server did because I asked another forum question in 2013 about it
https://forums.contribs.org/index.php/topic,49595.msg247989.html#msg247989 ........on further investigation........
I did a quick
grep "check_smtp_forward" /var/log/qpsmtpd/current | tai64nlocal
And it did show couple of entries all grouped within a few seconds today, here is one
2020-07-07 14:54:37.872340500 18093 (deny) logging::logterse: ` 80.12.70.35 relais-inet.orange.com relais-inet.orange.com <web.clients@orange.com> check_smtp_forward 902 Unable to connect to 10.42.0.3: msg denied before queued
So it looks to me like check_smtp_forward can reject emails when the internal exchange server is momentarily offline.
Which makes me think this could be an issue with the config of the exchange server, I wonder if it is configured to accept all email addresses and then generate bounces. I will go and visit the rather unpleasant exchange web config interface and report back.
Regards,
Mark Leman