I'm using non-authenticating accounts on stuff like iLO/iDRAC, some printers/copiers, UPS management software for alerts etc.
As for what you've told me and from what I understood after reading the relayclients wiki page, I have more questions. The way I see it, relayclients should contain addresses of hosts allowed to send mail without authentication, whereas norelayclients should contain a subset relayclients, for hosts that should authenticate, is that correct?
1) Atm, on my current 9.2 box relayclients contains only localhost and the ip address of itself. So, how come various devices on my lan are able to send email without authentication?
2) On the same box, norelayclients contains solely the gateway/upstream router ip address (my SME is operating in a server-only mode, without any gateway functionality). Why?
3) After reading the relayclients wiki, I believe I should modify relayclients to include a line 10.0.16.0/22 (my entire LAN range, which includes both normal users as well as devices sending unauthenticated alert emails, like iLO), whereas norelayclients should include 10.0.18.0/23 (since that is the ip range my normal users operate, hence authentication should be required). Did I get the hang of it right?