https://docs.microsoft.com/en-US/outlook/troubleshoot/profiles-and-accounts/cannot-connect-web-service-not-working-migrated-to-office-365
To resolve this issue, use one of the following methods.
Method 1: Use ExcludeLastKnownGoodUrl to prevent Outlook from using the last known good AutoDiscover URL
Configure one of the following registry subkeys as follows:
HKEY_CURRENT_USER\Software\Microsoft\Office\<x.0>\Outlook\Autodiscover
DWORD: ExcludeLastKnownGoodUrl
Value: 1
HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\<x.0>\Outlook\Autodiscover
DWORD: ExcludeLastKnownGoodUrl
Value: 1
Method 2: Create a new Outlook profile
Exit Outlook.
In Control Panel, select or double-click Mail.
Select Show Profiles.
Select Add.
Type a name for the profile, and then select OK.
Follow the Add Account wizard to add your email account. When you're done, select Finish.
In Mail, make sure that Always use this profile is selected, and then select your new profile name from the list.
Ok
