I completely failed to get it working, after 2 days activating / deactivating Plugins, altering settings adding and removing email settings, getting several techies at our hosting service to look at it, I gave up
Installed the free version WPForms and that’s now up and running
I guess Contact Form 7 is just too old, although it’s still working on other Websites of ours?
Here’s What others say
https://www.wpfixit.com/stop-using-contact-form-7-plugin/
go to the bottom of this page:
https://www.wpbeginner.com/plugins/5-best-contact-form-plugins-for-wordpress-compared/#aioseo-1-wpforms