Orbi AX6000 (RBR850) - blocking one of my email addresses in/out

(sometimes responses are perfectly clear to the person who wrote them, but might be a bit ambiguous when we read them.  Such as terms like "blocked")

• Bitdefender Armor is or is not enabled on this system?
• Smart Parental Controls is or is not enabled on this system?
• Has the system been power cycled?
• What email client system is being used?
• What specific error message is received?

Ii wholeheartedly agree that a total Factory Reset and reconfiguration can be an enormous chore. (In my case, it takes over two hours of typo-ridden data entry and a lot of swearing.)  It is indeed the last resort.

There is a short cut method of resetting firmware:

• Save a copy of the configuration to a computer using the menu item Backup Settings.
• Perform the Factory Reset maneuver with an object stuck into the tiny Reset hole.
  https://kb.netgear.com/31486/How-do-I-reset-my-Orbi-system-to-factory-default-settings 
• When the system restarts, connect the computer to the router and access the web interface using either http://orbilogin.net or the IP address of the router.
• This should bring up a web page encouraging use of the Orbi 'app' to configure the system.  IGNORE this off and select the link in tiny print I do not have a smartphone.
• Proceed to do the configuration, but:
  • Ignore any offers to register the system, enable Armor or Smart Parental Controls
  • Do not change the WiFi credentials from the default.
• Keep going until the page comes up asking if you want to:
  • Load a saved configuration, or
  • Continue with manual configuration
• Load the saved configuration.
• The system will reboot and the entire configuration comes back. (less any garbage that has crept into the system over the years).
• All WiFi devices will now connect as normal.

This entire process can be done in 10 minutes.