Using classic Outlook for Windows in business environments
Hi Louis! My name is Sally and I am an Independent Advisor and as well as a Microsoft user like you.
That is most probably a temporary fault: the security certificate presented by the server you connected to did not match the URL you are using to connect to it. Since you're using Delta Sync, this should all happen automatically and there must have been a hiccup at the particular server where your account is hosted. If it doesn't come right after a few hours, post back. Meanwhile, try closing down Windows Live Mail and waiting a few minutes before re-launching and trying again.
If you using outlook in browser I would suggest you to clear the browser and then login again or if you are using outlook app then I would suggest you to uninstall it and then again install it.
Please let me know, if there is anything else I can help with you.
Regards
Sally