Can't add webmail account from cpanel to new outlook.

New Outlook for Windows supports Microsoft 365 work or school accounts, Outlook.com/Hotmail, Gmail, Yahoo, iCloud, and other accounts that connect by IMAP or POP. It does not support on-premises Exchange accounts, and unsupported accounts can show connection errors.

Since the same 3 accounts work in Classic Outlook, use this troubleshooting path:

1. Confirm the account type in New Outlook
   • In New Outlook, go to View > View settings > Accounts > Your accounts.
   • Try adding the failing address again with Add Account.
   • If the account is being treated like a shared mailbox, open it instead from Settings > Accounts > Shared with me > Add.
2. If New Outlook shows an app password message
   • Some non-Microsoft providers require an app password for Outlook, especially for certain IMAP or iCloud-style connections.
   • Generate the app password on the mail provider side, then paste that app password into Outlook instead of the normal mailbox password.
3. Check whether the domain is still returning bad Autodiscover results
   • A known cause of setup failure is when the domain’s web hosting service responds incorrectly to Outlook Autodiscover requests after a Microsoft 365 or custom-domain mail change.
   • In that case, the fix is to have the web hosting or web service provider stop responding to Autodiscover requests for the root domain.
4. Work around stale Autodiscover data in Outlook
   • Create a new Outlook profile and add one of the failing accounts there:
     1. Exit Outlook.
     2. Open Control Panel > Mail.
     3. Select Show Profiles.
     4. Select Add.
     5. Enter a profile name and select OK.
     6. Use the Add Account wizard to add the mailbox.
     7. In Mail, set Always use this profile to the new profile.
   • This is the safest first step before registry changes.
5. If the problem started after the previous Google Workspace change and still persists
   • Outlook can keep using a last known good Autodiscover URL.
   • A documented workaround is to set the registry value ExcludeLastKnownGoodUrl = 1 under:
     • HKEY_CURRENT_USER\Software\Microsoft\Office\<x.0>\Outlook\Autodiscover
     • or HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\<x.0>\Outlook\Autodiscover
   • For the custom-domain Autodiscover issue, another documented workaround is ExcludeHttpsRootDomain = 1 under the same Autodiscover path.
   • Warning: registry changes can affect Outlook account discovery. Back up the registry first, then restart Outlook and try adding the account again.
6. If New Outlook still rejects only those 3 accounts
   • That points to a provider-side compatibility or Autodiscover problem for those specific mailboxes or the domain, not a general Outlook installation issue.
   • Classic Outlook working is a valid workaround while the provider-side configuration is corrected.

References:

• Supported accounts in new Outlook for Windows
• Add an email account to Outlook for Windows
• Outlook doesn't connect or web services don't work after migration to Microsoft 365
• Something went wrong and Outlook couldn't set up your account