Error Reporting from Your Systemd Automation

I use XMPP for this purpose: https://github.com/majewsky/xmpp-bridge

Service units then look like this: https://github.com/majewsky/system-configuration/blob/master... (the "with-xmpp-bridge" helper script is near the top of the same file)

The advantage of XMPP is that it can interactively ask me for confirmation, e.g. when installing upgrades, and that an XMPP server like Prosody is vastly simpler to set up than a mail server.

If you're just going to have systemd call a shell script every 15 mins... Why not just run sysvinit?