Update to this: I have the plugin health check & troubleshooting, so I tried testing the site with every other plugin disabled and a default theme and I still get the same error.
@mikenielsen9876 When I was reading about CF7 it said it uses the built in WP mail engine to send messages. After some research it seems the WP mail engine is a little wonky and prone to being flagged as spam. A friend recommended I try installing an SMTP plugin to use my mail settings from my site host. After I set that up, the mail started sending again. Like you, nothing had changed with my site and I’m not 100% sure when my messages stopped sending, but I’ve checked it everyday since Monday of this week and they are still sending now with the SMTP plugin activated.
Turns out this was an SMTP problem. I was able to resolve it with my host.
