Cannot delete Outlook profile from Mail settings

I have an old broken profile listed in Control Panel, Mail, Show Profiles. When I select it and click Remove, nothing happens. No error, no removal.

Outlook 2019 on Windows 10. I already set another profile as the default and it works. I just want the dead one gone.

When Remove goes silent it is almost always because something still has the profile open. Outlook itself, the Search indexer or a sync process can all hold a handle on it.

1

Close Outlook, then open Task Manager and end any OUTLOOK.EXE, UCMAPI.EXE or SearchProtocolHost.exe still running.

2

Try Remove again from Control Panel, Mail, Show Profiles.

3

If it still refuses, delete it in the registry. Open regedit and go to HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\Profiles. Right click the profile name key and delete it.

4

Delete the leftover data file. Look in %localappdata%\Microsoft\Outlook for an OST named after the dead profile account and remove it to reclaim the space.

Export the Profiles registry key first via File, Export in regedit. If you delete the wrong subkey you can merge the backup straight back.

UCMAPI.EXE was the culprit, it was still running ten minutes after I closed Outlook. Killed it and Remove worked without touching the registry.