Tools

Monitors

Uptime Robot

https://stats.uptimerobot.com/81NqJuOD8 Monitor sites’ uptime. We have up to 50 monitors for the free plan but I think it is lower now. Semdsnotifications when a site goes down. You can set it to check https, ping or http every 24 hours down to 5 mins (free plan).

StatusCake

This was being used to monitor uptime for the VPSs. It can monitor sites too. Uptime Robot allows us 50 which is enough so not using this any more.

Email

Mailinator

https://mailinator.com Great for testing site email, e.g. notifications. No need to set up any addresses, just send to anything@mailinator.com and then go to that inbox and your messages will show up there. Or not…

Dmarcian

Using Dmarcian to manage domains spf, dkim, dmarc etc.
There are video tutorials at https://dmarcian.com/videos-on-all-things-dmarc/
Trying to avoid using 3rd party email services so as to maintain user privacy and generally not contribute to the control freaks efforts to track everything everyone does.