Hi Lee Hutchinson2,
Welcome to Microsoft Community.
May I ask if you use Outlook or the Mail application of Windows when you see this error?
If 0x80072f19 is indeed a certificate problem as you said, would you please confirm that the Settings you changed are listed in Internet Options?
I think you can refer to the image below to turn off the check certificate Settings temporarily to see the effect:
- Click Search on the taskbar and type in Internet Options
- Once the Settings are open, click the "Advanced" TAB and uncheck the options in the diagram
Another option is to delete your iCloud account from your Mail app or Outlook and add it again to see if it works.
If there is anything unclear, please don't hesitate to tell me at any time.
Best Regards,
Manson - MSFT | Microsoft Community Support Specialist