https://learn.microsoft.com/en-us/answers/questions/1144046/outlook-365-application-error-1001-mail-is-not-syn
sfc /scannow Reboot Another possible fix: I deleted the GUID key from HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Identity\Identities Rebooted, worked after that Keywords: Microsoft Outlook, Exchange, 365, Email, Password, Needs Updating |