Managing personal Outlook.com account settings, security, and privacy
Thank you for your reply, Edwin. I tried your suggestion. The outlook email address was already in "My Info", so I set that to primary. Unfortunately the problem remained, so I set it back to the original email address.
The problem actually occurs when I try to get to the Microsoft Outlook website, before I get any chance to log in. I have tried turning off the firewall but to no avail. I have also tried using Chrome and Edge as well as Firefox. Same result.
To be honest, I have given up on Microsoft Outlook. I think it should be renamed "Look Out". It's useless if I can't access the webmail facility. I have instead started using Zoho instead - which works.
Anyhow, I appreciate you help.