I know it’s not everyone’s favourite but I use Nextcloud to manage family calendars and contacts and to sync between Mac, PC, iOS and Android.

A similar solution but I use https://ntfy.sh/ I have the app on my phone and have it set to alert when jobs ping the service. Mine ping on success but it is possible to ping when the job fails as well.

Agreed, if the box works for you I’d look at cycling out the drives - 10 years is a long time for spinning disks to last and every day is another day closer to a failure.