My home server (the client) despite a "noIP", always on the internet, IP address changes are very rear. I'm using a script for report "new" ip to freedns.org and it is logging.
My IP does not change from 2019.11.30. (that date when I was rebuild from scratch a new server based on Debian buster). At first time I could even use "mynetworks", may be accomplish with a local email if IP is changed, up to that time, when I find how to setup sasl authentication for exim4 as a client (or swap it with postfix, could be it is the best solution). Thank for your support! tovis